So if you want to make a developer laugh you can give them this one… It’s likely a pie-in-the-sky request but nothing asked is nothing gained.
BUT, it would be awesome if there was a very-granular solution to collision with the virtual heightfield-mesh.
Currently, it relies on the underlying mesh to provide collision. Landscapes suffice, and in the case of small-scale deformation, works perfectly well. Additionally given the collision of the landscape and the actual height of the heightfield-mesh can differ, allows for things like walking through ‘water’, stepping into puddles, or leaving trails in sand/snow/etc. I like options. 
However, with large-scale deformation, it’s very obvious as one just cruises on through geometry that there is no collision.
If you want to get collision to match material-driven deformation, one has to make the landscape very very small, and that comes with it’s own issues.
I get the lack of collision is part of how the heightfield-mesh currently works, but if all possible, being able to use shader-math to help drive this would be awesome. I don’t know if a second virtual texture could come into play, but maybe Santa will be Epic this year…