Tree operation: dummy dimensions and crashes

Hi! I notice two tree behaviors in my project that causes performance problems:
1 flattening, grafting, and simplifying tree: these crashes gh (when slow operations like solid union doesn’t?) and I need to restart the application for the problem to go away.
2 modules create dummy dimensions and I need to simplify every one of them
If I have each combo-curve grafted in a {x} list, I get start point in {0:x} and endpoint in {1:x} for seemingly no reason. This happens a lot and I often need to simplify multiple modules because my {x} tree turn into {0:0:0…0:x} trees (the extra dimensions are useless because they are the same for all branches)
Should I be looking for a solution that automatically simplifies the result (and keep restarting gh) or are 1 and 2 how things supposed to work?

Many thanks!