diff --git a/packages/oneclient_app/src/hooks/mod.rs b/packages/oneclient_app/src/hooks/mod.rs
index 9a029cad..9bc877bf 100644
--- a/packages/oneclient_app/src/hooks/mod.rs
+++ b/packages/oneclient_app/src/hooks/mod.rs
@@ -42,7 +42,7 @@ pub use queries::{
     use_package_project, use_package_search, use_package_versions, use_player_profile,
     use_player_skin, use_provider_versions, use_refresh_account, use_refresh_all_accounts,
     use_remove_account, use_screenshot_action, use_set_default_account, use_terms, use_upload_log,
-    use_version_metadata, use_versions, version_list, versions_total,
+    use_version_metadata, use_versions, version_list, versions_metadata, versions_total,
 };
 
 use crate::{
diff --git a/packages/oneclient_app/src/hooks/queries/mod.rs b/packages/oneclient_app/src/hooks/queries/mod.rs
index 15e563c3..f70c14e2 100644
--- a/packages/oneclient_app/src/hooks/queries/mod.rs
+++ b/packages/oneclient_app/src/hooks/queries/mod.rs
@@ -72,4 +72,4 @@ pub use settings_profiles::{
 pub use skin::use_player_skin;
 pub use tos::{TermsQuery, terms_document, terms_error, terms_is_loading, use_terms};
 pub use version_metadata::{pick_version_metadata, use_version_metadata};
-pub use versions::{loader_versions, use_loader_versions, use_versions};
+pub use versions::{loader_versions, use_loader_versions, use_versions, versions_metadata};
diff --git a/packages/oneclient_app/src/hooks/queries/version_metadata.rs b/packages/oneclient_app/src/hooks/queries/version_metadata.rs
index 644d4644..29fb3eab 100644
--- a/packages/oneclient_app/src/hooks/queries/version_metadata.rs
+++ b/packages/oneclient_app/src/hooks/queries/version_metadata.rs
@@ -84,6 +84,7 @@ mod tests {
             art_url: None,
             long_description: None,
             tags: Vec::new(),
+            predownload: false,
         }
     }
 
diff --git a/packages/oneclient_app/src/hooks/queries/versions.rs b/packages/oneclient_app/src/hooks/queries/versions.rs
index b48c48fb..c218ea33 100644
--- a/packages/oneclient_app/src/hooks/queries/versions.rs
+++ b/packages/oneclient_app/src/hooks/queries/versions.rs
@@ -28,6 +28,21 @@ pub fn use_versions() -> UseQuery<VersionsMetadataQuery> {
     use_query(Query::new(VersionsMetadataKeys, VersionsMetadataQuery))
 }
 
+/// The manifest rows once the query has settled, `None` while it is still
+/// loading. A failed fetch reads as an empty list rather than `None`, so
+/// callers that block on this don't wait forever when the network is down.
+pub fn versions_metadata(query: &UseQuery<VersionsMetadataQuery>) -> Option<Vec<VersionMetadata>> {
+    let reader = query.read();
+    match &*reader.state() {
+        QueryStateData::Settled { res: Ok(list), .. } => Some(list.clone()),
+        QueryStateData::Settled { res: Err(_), .. } => Some(Vec::new()),
+        QueryStateData::Loading {
+            res: Some(Ok(list)),
+        } => Some(list.clone()),
+        _ => None,
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct LoaderVersionsQuery;
 
diff --git a/packages/oneclient_app/src/view/onboarding/downloading/mod.rs b/packages/oneclient_app/src/view/onboarding/downloading/mod.rs
index af11f2b7..12c52dbd 100644
--- a/packages/oneclient_app/src/view/onboarding/downloading/mod.rs
+++ b/packages/oneclient_app/src/view/onboarding/downloading/mod.rs
@@ -7,7 +7,7 @@ use freya::router::RouterContext;
 use oneclient_core::notification::{
     GroupedProgressEvent, GroupedProgressSession, Notification, NotificationService,
 };
-use oneclient_core::{BundleArchive, BundleFile, ImportTarget};
+use oneclient_core::{BundleArchive, BundleFile, Cluster, ImportTarget, VersionMetadata};
 use oneclient_db::models::OverrideType;
 use tokio::sync::mpsc;
 use uuid::Uuid;
@@ -16,6 +16,7 @@ use crate::hooks::{
     BridgeDispatch, ClusterBundles, invalidate_cluster_queries, migration_detections,
     onboarding_bundles_items, try_default_account, use_current_account, use_dispatch,
     use_migration, use_onboarding_bundles, use_onboarding_selection, use_settings_snapshot,
+    use_versions, versions_metadata,
 };
 use crate::routes::Route;
 use crate::theme::colors;
@@ -40,6 +41,9 @@ struct ClusterPlan {
     /// `(bundle_name, package_id, override)` for every file whose fate differs
     /// from the bundle manifest's default.
     overrides: Vec<(String, String, OverrideType)>,
+    /// The manifest's `predownload` flag for this version. Versions without it
+    /// only ever record their package choices here and fetch on first launch.
+    predownload: bool,
 }
 
 #[derive(Clone, PartialEq)]
@@ -193,6 +197,7 @@ impl Component for OnboardingDownloading {
         let dispatch = use_dispatch();
         let bundles_query = use_onboarding_bundles();
         let migration_query = use_migration();
+        let versions_query = use_versions();
         let selection = use_onboarding_selection();
         let settings = use_settings_snapshot().settings;
         let account_query = use_current_account();
@@ -237,8 +242,11 @@ impl Component for OnboardingDownloading {
             let Some(items) = onboarding_bundles_items(&bundles_query) else {
                 return;
             };
+            let Some(versions) = versions_metadata(&versions_query) else {
+                return;
+            };
             let selected = selected_state.peek().clone();
-            let plans = build_plans(&items, &selected);
+            let plans = build_plans(&items, &selected, &versions);
             let predownload = *predownload_state.peek();
             started.set(true);
             run_install_batch(plans, predownload, handles);
@@ -341,6 +349,7 @@ impl Component for OnboardingDownloading {
             return summary_view(
                 &items,
                 &selected,
+                &versions_metadata(&versions_query).unwrap_or_default(),
                 &language,
                 reduce_motion,
                 settings.dynamic_background_enabled,
@@ -440,6 +449,7 @@ impl Component for OnboardingDownloading {
 fn build_plans(
     items: &[ClusterBundles],
     selected: &std::collections::HashSet<String>,
+    versions: &[VersionMetadata],
 ) -> Vec<ClusterPlan> {
     items
         .iter()
@@ -452,11 +462,26 @@ fn build_plans(
                 cluster_id: cb.cluster.id,
                 mc_version: cb.cluster.mc_version.clone(),
                 overrides,
+                predownload: cluster_predownloads(versions, &cb.cluster),
             }
         })
         .collect()
 }
 
+/// Whether the manifest asks for this cluster's version to be fetched up front.
+/// Clusters with no manifest row (e.g. seeded from the bundle catalog alone)
+/// are not predownloaded.
+fn cluster_predownloads(versions: &[VersionMetadata], cluster: &Cluster) -> bool {
+    let loader = cluster.mc_loader.to_string();
+    versions.iter().any(|m| {
+        m.predownload
+            && m.mc_version().as_deref() == Some(cluster.mc_version.as_str())
+            && m.loader
+                .as_deref()
+                .is_none_or(|l| l.eq_ignore_ascii_case(&loader))
+    })
+}
+
 fn archive_overrides(
     cluster_id: i64,
     archive: &BundleArchive,
@@ -505,9 +530,13 @@ const JRE_SIZE_GUESS: u64 = 45_000_000;
 fn rough_download_estimate(
     items: &[ClusterBundles],
     selected: &std::collections::HashSet<String>,
+    versions: &[VersionMetadata],
 ) -> u64 {
     let mut total: u64 = 0;
     for cb in items {
+        if !cluster_predownloads(versions, &cb.cluster) {
+            continue;
+        }
         for archive in &cb.archives {
             let dropped: std::collections::HashSet<String> =
                 archive_overrides(cb.cluster.id, archive, selected)
@@ -646,7 +675,7 @@ fn run_install_batch(plans: Vec<ClusterPlan>, predownload: bool, handles: Instal
             ));
             if let Ok(state) = oneclient_core::LauncherState::get() {
                 let mut sum = 0u64;
-                for plan in &plans {
+                for plan in plans.iter().filter(|p| p.predownload) {
                     match oneclient_core::estimate_cluster_download(
                         &state,
                         plan.cluster_id,
@@ -672,7 +701,8 @@ fn run_install_batch(plans: Vec<ClusterPlan>, predownload: bool, handles: Instal
                 label: plan.mc_version.clone(),
             }));
 
-            if let Err(reason) = install_one(&plan, predownload, &notifier, &ui_tx).await {
+            let fetch_now = predownload && plan.predownload;
+            if let Err(reason) = install_one(&plan, fetch_now, &notifier, &ui_tx).await {
                 tracing::error!(
                     cluster_id = plan.cluster_id,
                     mc_version = %plan.mc_version,
@@ -868,10 +898,29 @@ mod tests {
             .collect()
     }
 
+    /// Manifest row matching `test_support::cluster` (1.21.11 fabric).
+    fn version_row(predownload: bool) -> VersionMetadata {
+        VersionMetadata {
+            major_version: 21,
+            minor_version: Some(11),
+            patch_version: None,
+            loader: Some("fabric".to_string()),
+            name: "Mounts of Mayhem".to_string(),
+            art_url: None,
+            long_description: None,
+            tags: Vec::new(),
+            predownload,
+        }
+    }
+
+    fn versions() -> Vec<VersionMetadata> {
+        vec![version_row(true)]
+    }
+
     #[test]
     fn declining_a_bundle_removes_its_visible_and_hidden_files() {
         let sb = skyblock();
-        let plans = build_plans(&items(vec![sb.clone()]), &HashSet::new());
+        let plans = build_plans(&items(vec![sb.clone()]), &HashSet::new(), &versions());
 
         let ov = &plans[0].overrides;
         // The hidden dependency must be dropped too, or it installs anyway.
@@ -892,7 +941,7 @@ mod tests {
     fn accepting_a_bundle_records_nothing_for_its_defaults() {
         let sb = skyblock();
         let selected = keys(&sb, &["skyblock-main"]);
-        let plans = build_plans(&items(vec![sb.clone()]), &selected);
+        let plans = build_plans(&items(vec![sb.clone()]), &selected, &versions());
 
         assert!(plans[0].overrides.is_empty());
     }
@@ -901,7 +950,7 @@ mod tests {
     fn opting_into_an_extra_writes_enabled() {
         let sb = skyblock();
         let selected = keys(&sb, &["skyblock-main", "skycubed"]);
-        let plans = build_plans(&items(vec![sb.clone()]), &selected);
+        let plans = build_plans(&items(vec![sb.clone()]), &selected, &versions());
 
         assert_eq!(
             plans[0].overrides,
@@ -917,7 +966,7 @@ mod tests {
     fn an_extra_alone_still_keeps_hidden_dependencies() {
         let sb = skyblock();
         let selected = keys(&sb, &["skycubed"]);
-        let plans = build_plans(&items(vec![sb.clone()]), &selected);
+        let plans = build_plans(&items(vec![sb.clone()]), &selected, &versions());
         let ov = &plans[0].overrides;
 
         assert!(ov.contains(&(
@@ -935,7 +984,7 @@ mod tests {
 
     #[test]
     fn rejections_are_removed_never_disabled() {
-        let plans = build_plans(&items(vec![skyblock()]), &HashSet::new());
+        let plans = build_plans(&items(vec![skyblock()]), &HashSet::new(), &versions());
 
         assert!(
             !plans[0]
@@ -959,7 +1008,7 @@ mod tests {
             },
         ];
         let selected: HashSet<String> = [pkg_key(1, &sb.manifest.name, "skyblock-main")].into();
-        let plans = build_plans(&both, &selected);
+        let plans = build_plans(&both, &selected, &versions());
 
         assert!(plans[0].overrides.is_empty());
         assert!(
@@ -976,13 +1025,48 @@ mod tests {
         let all = items(vec![sb.clone()]);
         let baseline = GAME_SIZE_GUESS + JRE_SIZE_GUESS;
 
-        let declined = rough_download_estimate(&all, &HashSet::new());
+        let declined = rough_download_estimate(&all, &HashSet::new(), &versions());
         assert_eq!(declined, baseline, "declined bundle should cost nothing");
 
-        let accepted = rough_download_estimate(&all, &keys(&sb, &["skyblock-main"]));
+        let accepted = rough_download_estimate(&all, &keys(&sb, &["skyblock-main"]), &versions());
         assert_eq!(accepted, baseline + 2);
 
-        let with_extra = rough_download_estimate(&all, &keys(&sb, &["skyblock-main", "skycubed"]));
+        let with_extra = rough_download_estimate(
+            &all,
+            &keys(&sb, &["skyblock-main", "skycubed"]),
+            &versions(),
+        );
         assert_eq!(with_extra, baseline + 3);
     }
+
+    #[test]
+    fn plans_take_predownload_from_the_manifest() {
+        let all = items(vec![skyblock()]);
+        assert!(build_plans(&all, &HashSet::new(), &versions())[0].predownload);
+        assert!(!build_plans(&all, &HashSet::new(), &[version_row(false)])[0].predownload);
+        // A cluster with no manifest row at all is never predownloaded.
+        assert!(!build_plans(&all, &HashSet::new(), &[])[0].predownload);
+    }
+
+    #[test]
+    fn a_predownload_row_for_another_version_does_not_match() {
+        let mut other = version_row(true);
+        other.minor_version = Some(10);
+        assert!(!build_plans(&items(vec![skyblock()]), &HashSet::new(), &[other])[0].predownload);
+    }
+
+    #[test]
+    fn a_predownload_row_for_another_loader_does_not_match() {
+        let mut other = version_row(true);
+        other.loader = Some("forge".to_string());
+        assert!(!build_plans(&items(vec![skyblock()]), &HashSet::new(), &[other])[0].predownload);
+    }
+
+    #[test]
+    fn the_estimate_ignores_versions_that_are_not_predownloaded() {
+        let all = items(vec![skyblock()]);
+        let selected = keys(&skyblock(), &["skyblock-main"]);
+
+        assert_eq!(rough_download_estimate(&all, &selected, &[]), 0);
+    }
 }
diff --git a/packages/oneclient_app/src/view/onboarding/downloading/summary.rs b/packages/oneclient_app/src/view/onboarding/downloading/summary.rs
index ff5d2c98..9796a390 100644
--- a/packages/oneclient_app/src/view/onboarding/downloading/summary.rs
+++ b/packages/oneclient_app/src/view/onboarding/downloading/summary.rs
@@ -14,6 +14,7 @@ use crate::view::onboarding::{onboarding_illustration, predownload_toggle_row, s
 pub(super) fn summary_view(
     items: &[ClusterBundles],
     selected: &std::collections::HashSet<String>,
+    versions: &[VersionMetadata],
     language: &str,
     reduce_motion: bool,
     parallax: bool,
@@ -34,10 +35,26 @@ pub(super) fn summary_view(
         })
         .collect();
 
-    let packages_note = if *predownload.read() {
-        let est = rough_download_estimate(items, selected);
+    let ready_now = items
+        .iter()
+        .filter(|cb| cluster_predownloads(versions, &cb.cluster))
+        .count();
+
+    let packages_note = if *predownload.read() && ready_now > 0 {
+        let est = rough_download_estimate(items, selected, versions);
+        let (scope, rest) = if ready_now == items.len() {
+            ("Your selected content is".to_string(), "")
+        } else {
+            (
+                format!(
+                    "Content for {ready_now} version{} is",
+                    if ready_now == 1 { "" } else { "s" }
+                ),
+                " Everything else is downloaded the first time you launch it.",
+            )
+        };
         format!(
-            "Your selected content is downloaded now, during setup. About {} total.",
+            "{scope} downloaded now, during setup. About {} total.{rest}",
             format_size(est)
         )
     } else {
diff --git a/packages/oneclient_core/src/versions/manifest.rs b/packages/oneclient_core/src/versions/manifest.rs
index 2e0c8143..f779cb34 100644
--- a/packages/oneclient_core/src/versions/manifest.rs
+++ b/packages/oneclient_core/src/versions/manifest.rs
@@ -1,7 +1,7 @@
 use serde::{Deserialize, Serialize};
 
 use crate::api_config::meta_url_base;
-use crate::version::VersionKey;
+use crate::version::{VersionKey, format_mc_version};
 
 #[derive(Debug, Default, Clone, PartialEq, Serialize, Deserialize)]
 pub struct VersionsManifest {
@@ -22,6 +22,9 @@ pub struct RemoteCluster {
     pub long_description: Option<String>,
     #[serde(default)]
     pub tags: Vec<String>,
+    /// Default for every entry in this cluster; an entry's own key wins.
+    #[serde(default)]
+    pub predownload: Option<bool>,
     #[serde(default)]
     pub entries: Vec<RemoteEntry>,
 }
@@ -41,6 +44,8 @@ pub struct RemoteEntry {
     pub long_description: Option<String>,
     #[serde(default)]
     pub tags: Option<Vec<String>>,
+    #[serde(default)]
+    pub predownload: Option<bool>,
 }
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
@@ -71,6 +76,9 @@ pub struct VersionMetadata {
     pub art_url: Option<String>,
     pub long_description: Option<String>,
     pub tags: Vec<String>,
+    /// Whether this version is fetched up front during onboarding, rather than
+    /// on first launch. Cluster rows carry the cluster's own default.
+    pub predownload: bool,
 }
 
 impl VersionMetadata {
@@ -78,6 +86,17 @@ impl VersionMetadata {
     pub fn key(&self) -> Option<VersionKey> {
         Some((self.minor_version?, self.patch_version))
     }
+
+    /// The `mc_version` string this row maps to, or `None` for the synthetic
+    /// cluster-level row (which has no minor version of its own).
+    #[must_use]
+    pub fn mc_version(&self) -> Option<String> {
+        Some(format_mc_version(
+            self.major_version,
+            self.minor_version?,
+            self.patch_version,
+        ))
+    }
 }
 
 fn art_url(path: &Option<String>) -> Option<String> {
@@ -104,6 +123,7 @@ impl VersionsManifest {
                 art_url: art_url(&cluster.art),
                 long_description: cluster.long_description.clone(),
                 tags: cluster.tags.clone(),
+                predownload: cluster.predownload.unwrap_or(false),
             });
 
             for entry in &cluster.entries {
@@ -119,6 +139,7 @@ impl VersionsManifest {
                         .clone()
                         .or_else(|| cluster.long_description.clone()),
                     tags: entry.tags.clone().unwrap_or_else(|| cluster.tags.clone()),
+                    predownload: entry.predownload.or(cluster.predownload).unwrap_or(false),
                 });
             }
         }
@@ -165,6 +186,56 @@ mod tests {
         assert_eq!(entry.key(), Some((1, Some(2))));
     }
 
+    #[test]
+    fn predownload_inherits_from_cluster_and_entry_overrides() {
+        let manifest: VersionsManifest = serde_json::from_str(
+            r#"{"clusters":[
+                {"major_version":26,"predownload":true,"entries":[
+                    {"minor_version":1},
+                    {"minor_version":2,"predownload":false}
+                ]},
+                {"major_version":21,"entries":[
+                    {"minor_version":1},
+                    {"minor_version":11,"predownload":true}
+                ]}
+            ]}"#,
+        )
+        .expect("should parse");
+
+        let metadata = manifest.metadata();
+        let flag = |major: u32, minor: Option<u32>| {
+            metadata
+                .iter()
+                .find(|m| m.major_version == major && m.minor_version == minor)
+                .expect("row present")
+                .predownload
+        };
+
+        // Cluster default flows down to entries that stay silent.
+        assert!(flag(26, None));
+        assert!(flag(26, Some(1)));
+        // An entry's own key wins over the cluster default, in both directions.
+        assert!(!flag(26, Some(2)));
+        assert!(flag(21, Some(11)));
+        // Absent everywhere means off.
+        assert!(!flag(21, None));
+        assert!(!flag(21, Some(1)));
+    }
+
+    #[test]
+    fn mc_version_skips_the_cluster_row() {
+        let manifest: VersionsManifest = serde_json::from_str(
+            r#"{"clusters":[{"major_version":26,"entries":[
+                {"minor_version":1,"patch_version":2}
+            ]}]}"#,
+        )
+        .expect("should parse");
+
+        let metadata = manifest.metadata();
+        assert_eq!(metadata[0].mc_version(), None);
+        assert_eq!(metadata[1].mc_version().as_deref(), Some("26.1.2"));
+    }
+
     #[test]
     fn migrations_parse() {
         let manifest: VersionsManifest = serde_json::from_str(