@User and @User the multicorner STA should not be increasing the time spent in removing instances in opendb. This time increase can be caused during repairing the design. I think it likely that a lot more repair work is now being done because the STA is more comprehensive. If you could paste a screenshot of your vtune run showing the critical call stack we could verify.

Yeah that was a red herring. I think the extra time is because we are doing 3x the STA runs now (3 -> 9)

There is an issue with dbInst::destroy performance that Mohamed has fixed and will PR soon (removing from a singly linked list in O(n) and is changed to doubly linked O(1))

That will be good to fix! We want all the basic netlist edits to be O(1).