на 28.10 рабочая версия, даже без лага на выборе этажа

Config/DefaultEngine.ini

@@ -23,7 +23,7 @@ r.MinScreenRadiusForDepthPrepass=0.100000
 r.EarlyZPassOnlyMaterialMasking=False
 r.GBufferFormat=1
 r.DefaultFeature.MotionBlur=False
-r.ClearSceneMethod=0
+r.ClearSceneMethod=1
 r.AllowGlobalClipPlane=True
 r.GPUSkin.Limit2BoneInfluences=False
 
@@ -179,3 +179,11 @@ bEnableLegacyReverb=True
 [/Script/AndroidRuntimeSettings.AndroidRuntimeSettings]
 AudioNumBuffersToEnqueue=4
 
+[/Script/Engine.StreamingSettings]
+s.AsyncLoadingUseFullTimeLimit=False
+s.AsyncLoadingTimeLimit=1.000000
+s.PriorityAsyncLoadingExtraTime=5.000000
+s.LevelStreamingActorsUpdateTimeLimit=1.000000
+s.PriorityLevelStreamingActorsUpdateExtraTime=5.000000
+s.LevelStreamingComponentsUnregistrationGranularity=1
+s.UseBackgroundLevelStreaming=True