Hello I saw that you have Problems with the Edges. I made a similar System and continue with it, you can see in my Devlog. Its all in Blueprint rightnow as performance is oke enough.
DevLog#01 - Sims like building, walls, floor, windows and doors in Unreal Engine 4 - YouTube](DevLog#01 - Sims like building, walls, floor, windows and doors in Unreal Engine 4 - YouTube)