diff --git a/lib/src/components/header/HeaderMenuExtra.tsx b/lib/src/components/header/HeaderMenuExtra.tsx
index b3c977d1..35c6aa82 100644
--- a/lib/src/components/header/HeaderMenuExtra.tsx
+++ b/lib/src/components/header/HeaderMenuExtra.tsx
@@ -9,8 +9,6 @@ import Visibility from '@mui/icons-material/Visibility'
 import FilterAlt from '@mui/icons-material/FilterAlt'
 import Search from '@mui/icons-material/Search'
 import PhotoCamera from '@mui/icons-material/PhotoCamera'
-import RestartAlt from '@mui/icons-material/RestartAlt'
-import FolderOpen from '@mui/icons-material/FolderOpen'
 import Settings from '@mui/icons-material/Settings'
 import Assignment from '@mui/icons-material/Assignment'
 import List from '@mui/icons-material/List'
diff --git a/lib/src/model.ts b/lib/src/model.ts
index b7c04b34..2c5dd1c6 100644
--- a/lib/src/model.ts
+++ b/lib/src/model.ts
@@ -258,7 +258,7 @@ function stateModelFactory() {
        * #volatile
        * size of blocks of content to be drawn, px
        */
-      blockSize: 1000,
+      blockSize: 500,
 
       /**
        * #volatile
@@ -738,6 +738,17 @@ function stateModelFactory() {
         }
         return r
       },
+
+      /**
+       * #getter
+       */
+      get colStatsSums() {
+        return Object.fromEntries(
+          Object.entries(this.colStats).map(([key, val]) => {
+            return [key, sum(Object.values(val))]
+          }),
+        )
+      },
       /**
        * #getter
        * generates a new tree that is clustered with x,y positions
@@ -1321,6 +1332,17 @@ function stateModelFactory() {
           }),
         )
 
+        addDisposer(
+          self,
+          autorun(() => {
+            // force colStats not to go stale,
+            // xref solution https://github.com/mobxjs/mobx/issues/266#issuecomment-222007278
+            // xref problem https://github.com/GMOD/react-msaview/issues/75
+            self.colStats
+            self.colStatsSums
+            self.columns
+          }),
+        )
         // autorun synchronizes treeWidth with treeAreaWidth
         addDisposer(
           self,
diff --git a/lib/src/model/DataModel.ts b/lib/src/model/DataModel.ts
index 6cd09243..0542cb6b 100644
--- a/lib/src/model/DataModel.ts
+++ b/lib/src/model/DataModel.ts
@@ -43,4 +43,14 @@ export function DataModelF() {
         self.treeMetadata = treeMetadata
       },
     }))
+    .postProcessSnapshot(snap => {
+      const { tree, msa, treeMetadata } = snap
+      const max = 50_000
+      return {
+        tree: tree && tree.length > max ? undefined : tree,
+        msa: msa && msa.length > max ? undefined : msa,
+        treeMetadata:
+          treeMetadata && treeMetadata.length > max ? undefined : treeMetadata,
+      }
+    })
 }
diff --git a/lib/src/util.ts b/lib/src/util.ts
index ad88d4d1..f5ec88de 100644
--- a/lib/src/util.ts
+++ b/lib/src/util.ts
@@ -106,8 +106,6 @@ export function collapse(d: HierarchyNode<NodeWithIds>) {
     // @ts-expect-error
     d._children = d.children
     // @ts-expect-error
-    // d._children.forEach(collapse)
-    // @ts-expect-error
     d.children = null
   }
 }