Unroll trimmed surface vs not trimmed surface

Why does it takes much more time to unroll a trimmed surface vs a not trimmed.
Command flattening surface in rhino 5 was always much faster also

trimmed vs untrimmed.3dm (968.2 KB)


I’d assume because your trim curve has a lot of points and those need to be unrolled

I know, but the trim curve was a nice clean curve before I projected that curve.
How can I clean up the trim curve so it will take less time?
I also tried it whitout projecting, I just trimed it in side view, same result

solved for now
When I set the units from 0,001 to 0,1 it goes much faster