Our game has a system where the cursor color is changed when it’s over something clickable and in some some special cases it actually sets the cursor twice per frame (first to plain, then to highlighted). In the editor this happens instantaneously, but I noticed that in Windows builds (Windows 7) it actually took 33ms per frame.
Did some digging, noticed that Cursor.SetCursor takes a long time in the builds whenever it actually changes the texture. Changing once was about ~15 ms, twice ~33 ms and so on. 3 calls in one frame takes 50 ms. Seemed like it’s waiting for screen refresh, so I added a Thread.Sleep(10); just before and profiled again and now Cursor.SetCursor took about 10 ms which seems to confirm it.
I reported a bug too, Case 721323.