diff --git a/ydb/core/tablet_flat/flat_executor.cpp b/ydb/core/tablet_flat/flat_executor.cpp
index 58ca70001c3f..d46455f49554 100644
--- a/ydb/core/tablet_flat/flat_executor.cpp
+++ b/ydb/core/tablet_flat/flat_executor.cpp
@@ -4321,7 +4321,7 @@ ui64 TExecutor::BeginCompaction(THolder<NTable::TCompactionParams> params)
 
     comp->Epoch = snapshot->Subset->Epoch(); /* narrows requested to actual */
     comp->Layout.Final = comp->Params->IsFinal;
-    comp->Layout.WriteBTreeIndex = AppData()->FeatureFlags.GetEnableLocalDBBtreeIndex();
+    comp->Layout.WriteBTreeIndex = false; // will be in 24-2: AppData()->FeatureFlags.GetEnableLocalDBBtreeIndex();
     comp->Writer.StickyFlatIndex = !comp->Layout.WriteBTreeIndex;
     comp->Layout.MaxRows = snapshot->Subset->MaxRows();
     comp->Layout.ByKeyFilter = tableInfo->ByKeyFilter;
diff --git a/ydb/core/tablet_flat/flat_executor_ut.cpp b/ydb/core/tablet_flat/flat_executor_ut.cpp
index 18d8399728bf..52f2bb32a940 100644
--- a/ydb/core/tablet_flat/flat_executor_ut.cpp
+++ b/ydb/core/tablet_flat/flat_executor_ut.cpp
@@ -5491,7 +5491,7 @@ Y_UNIT_TEST_SUITE(TFlatTableExecutorBTreeIndex) {
         UNIT_ASSERT_VALUES_EQUAL(failedAttempts, 288);
     }
 
-    Y_UNIT_TEST(UseBtreeIndex_True) {
+    Y_UNIT_TEST(UseBtreeIndex_True) { // forcibly disabled in 24-1, uses FlatIndex
         TMyEnvBase env;
         TRowsModel rows;
 
@@ -5512,8 +5512,8 @@ Y_UNIT_TEST_SUITE(TFlatTableExecutorBTreeIndex) {
         env.SendSync(new NFake::TEvCompact(TRowsModel::TableId));
         env.WaitFor<NFake::TEvCompacted>();
 
-        // all pages are always kept in shared cache (except flat index)
-        UNIT_ASSERT_VALUES_EQUAL(counters->ActivePages->Val(), 334);
+        // all pages are always kept in shared cache
+        UNIT_ASSERT_VALUES_EQUAL(counters->ActivePages->Val(), 290);
 
         env.SendSync(new NFake::TEvExecute{ new TTxFullScan(readRows, failedAttempts) });
         UNIT_ASSERT_VALUES_EQUAL(readRows, 1000);
@@ -5526,96 +5526,9 @@ Y_UNIT_TEST_SUITE(TFlatTableExecutorBTreeIndex) {
         // after restart we have no pages in private cache
         env.SendSync(new NFake::TEvExecute{ new TTxFullScan(readRows, failedAttempts) }, true);
         UNIT_ASSERT_VALUES_EQUAL(readRows, 1000);
-        UNIT_ASSERT_VALUES_EQUAL(failedAttempts, 332);
-    }
-
-    Y_UNIT_TEST(UseBtreeIndex_True_TurnOff) {
-        TMyEnvBase env;
-        TRowsModel rows;
-
-        auto &appData = env->GetAppData();
-        appData.FeatureFlags.SetEnableLocalDBBtreeIndex(true);
-        auto counters = MakeIntrusive<TSharedPageCacheCounters>(env->GetDynamicCounters());
-        int readRows = 0, failedAttempts = 0;
-
-        env.FireDummyTablet(ui32(NFake::TDummy::EFlg::Comp));
-
-        auto policy = MakeIntrusive<TCompactionPolicy>();
-        policy->MinBTreeIndexNodeSize = 128;
-        env.SendSync(rows.MakeScheme(std::move(policy)));
-
-        env.SendSync(rows.VersionTo(TRowVersion(1, 10)).RowTo(0).MakeRows(1000, 950));
-        env.SendSync(rows.VersionTo(TRowVersion(2, 20)).RowTo(0).MakeRows(1000, 950));
-        
-        env.SendSync(new NFake::TEvCompact(TRowsModel::TableId));
-        env.WaitFor<NFake::TEvCompacted>();
-
-        // all pages are always kept in shared cache (except flat index)
-        UNIT_ASSERT_VALUES_EQUAL(counters->ActivePages->Val(), 334);
-
-        env.SendSync(new NFake::TEvExecute{ new TTxFullScan(readRows, failedAttempts) });
-        UNIT_ASSERT_VALUES_EQUAL(readRows, 1000);
-        UNIT_ASSERT_VALUES_EQUAL(failedAttempts, 0);
-
-        // restart tablet, turn off setting
-        env.SendSync(new TEvents::TEvPoison, false, true);
-        appData.FeatureFlags.SetEnableLocalDBBtreeIndex(false);
-        env.FireDummyTablet(ui32(NFake::TDummy::EFlg::Comp));
-
-        // after restart we have no pages in private cache
-        // but use only flat index
-        env.SendSync(new NFake::TEvExecute{ new TTxFullScan(readRows, failedAttempts) }, true);
-        UNIT_ASSERT_VALUES_EQUAL(readRows, 1000);
         UNIT_ASSERT_VALUES_EQUAL(failedAttempts, 288);
     }
 
-    Y_UNIT_TEST(UseBtreeIndex_True_Generations) {
-        TMyEnvBase env;
-        TRowsModel rows;
-
-        auto &appData = env->GetAppData();
-        appData.FeatureFlags.SetEnableLocalDBBtreeIndex(true);
-        auto counters = MakeIntrusive<TSharedPageCacheCounters>(env->GetDynamicCounters());
-        int readRows = 0, failedAttempts = 0;
-
-        env.FireDummyTablet(ui32(NFake::TDummy::EFlg::Comp));
-
-        auto policy = MakeIntrusive<TCompactionPolicy>();
-        policy->MinBTreeIndexNodeSize = 128;
-        policy->Generations.push_back({100 * 1024, 2, 2, 200 * 1024, NLocalDb::LegacyQueueIdToTaskName(1), false});
-        for (auto& gen : policy->Generations) {
-            gen.ExtraCompactionPercent = 0;
-            gen.ExtraCompactionMinSize = 0;
-            gen.ExtraCompactionExpPercent = 0;
-            gen.ExtraCompactionExpMaxSize = 0;
-            gen.UpliftPartSize = 0;
-        }
-        env.SendSync(rows.MakeScheme(std::move(policy)));
-
-        env.SendSync(rows.VersionTo(TRowVersion(1, 10)).RowTo(0).MakeRows(1000, 950));
-        env.SendSync(rows.VersionTo(TRowVersion(2, 20)).RowTo(0).MakeRows(1000, 950));
-
-        env.SendSync(new NFake::TEvCompact(TRowsModel::TableId));
-        env.WaitFor<NFake::TEvCompacted>();
-
-        // gen 0 data pages are always kept in shared cache
-        // b-tree index pages are always kept in shared cache
-        UNIT_ASSERT_VALUES_EQUAL(counters->ActivePages->Val(), 48);
-
-        env.SendSync(new NFake::TEvExecute{ new TTxFullScan(readRows, failedAttempts) });
-        UNIT_ASSERT_VALUES_EQUAL(readRows, 1000);
-        UNIT_ASSERT_VALUES_EQUAL(failedAttempts, 286);
-
-        // restart tablet
-        env.SendSync(new TEvents::TEvPoison, false, true);
-        env.FireDummyTablet(ui32(NFake::TDummy::EFlg::Comp));
-
-        // after restart we have no pages in private cache
-        env.SendSync(new NFake::TEvExecute{ new TTxFullScan(readRows, failedAttempts) }, true);
-        UNIT_ASSERT_VALUES_EQUAL(readRows, 1000);
-        UNIT_ASSERT_VALUES_EQUAL(failedAttempts, 332);
-    }
-
 }
 
 } // namespace NTabletFlatExecutor
diff --git a/ydb/core/tablet_flat/flat_part_loader.cpp b/ydb/core/tablet_flat/flat_part_loader.cpp
index 294e2be31516..127219f2ca53 100644
--- a/ydb/core/tablet_flat/flat_part_loader.cpp
+++ b/ydb/core/tablet_flat/flat_part_loader.cpp
@@ -78,7 +78,7 @@ void TLoader::StageParseMeta() noexcept
 
         BTreeGroupIndexes.clear();
         BTreeHistoricIndexes.clear();
-        if (AppData()->FeatureFlags.GetEnableLocalDBBtreeIndex()) {
+        if (false) { // will be in 24-2: AppData()->FeatureFlags.GetEnableLocalDBBtreeIndex()
             for (bool history : {false, true}) {
                 for (const auto &meta : history ? layout.GetBTreeHistoricIndexes() : layout.GetBTreeGroupIndexes()) {
                     NPage::TBtreeIndexMeta converted{{