Incremental GC vs Loading Screens deadlock

A licensee is reporting that using a loading screen with the incremental garbage collector can result in a dead lock when a loading screen is displayed. The licensee found out that: 

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This deadlock occurs when the SlateLoadingThread's main loop attempts to acquire a FSlateRHIResourceManager's critical section which was already locked by FSlateRHIResourceManager::OnPreGarbageCollect() when it started incremental reachability analysis.

The critical section remains locked because the Game Thread ends up stuck in FSlateLoadingSynchronizationMechanism::DestroySlateThread() which requires SlateLoadingThread3 to progress and FSlateRHIResourceManager::OnPostGarbageCollect() can never be called since the game thread is spinning and unable to allow incremental GC to finish.

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From the UDN case: 

DefaultEngine.ini:

[/Script/Engine.GarbageCollectionSettings]

gc.AllowIncrementalReachability=True

gc.AllowIncrementalGather=True

gc.IncrementalGatherTimeLimit=0.00125

gc.IncrementalReachabilityTimeLimit=0.00125

1) Run client and load initial map complex enough for reachability analysis to take several ms

2) Trigger travel to a different map