@CoquiGames Thanks for the feedback. I haven’t gotten to reducing the compile time yet but it is in my todo list.
I believe if the code exposes all the necessary parameters from the auto-generated master material and change those params from the assigned dynamic material instance, it would not trigger a recompile (also the result in the viewport is immediate). Since the master material network wouldn’t need to be changed when you are modifying the geometry or painting the landscape, it shouldn’t trigger a recompile when the height or weights are modified on a layer. I briefly experimented with this and it looks like it should work, i might be wrong though 
That makes sense. I’ll support a workflow like this
Not at all 
Your feedback will help improve it