Realtime deformation; collision breaking in places

Hey guys,

Really stuck here, cant get my collisions on my landscape to properly update after deformation events (negative z offsets) Screen capture - c7f578ad07e42482683f0aa7ec89891b - Gyazo -(Structural crater) As you can see it “works” just barely - I cant find any guidance on this but I am really expended right now so maybe my keywords are a bit outdated.

Been a real long night now and no luck in fixing my issue. Please excuse the broken tess/vpaint etc, the params have been slammed and clamped for this testing - also that isometric dude is not rendering correctly because the camera its designed to always face being in the sky at the expected isometric angle (Don’t judge me XD). I got some people I would very much like to show my structures collapsing to today; It would be very very nice if it fell into the crater it leaves. Better still if my dudes grenades would stop making “death-holes” (Too small a deform crater?)

Some info; I am very simply unmasking the relatively highly offset material function inside the layer blend to achieve this atm, slamming down tess mult on overlaying layers that get “blown away”. I dont think its a mat problem but If anyone with knowledge of this subject could give any direction I would be appreciative!