Executive is a Trojan.
It will crash just about any software that launches subtasks. Or it will cause a race condition so that the main task or subtask or both get stuck forever.
Executive is completely bogus and should be deleted immediately.
A programmer friend of mine has explained to me some other bugs that Executive overwrites into your Operating System but I can't quite recall what they were.
The Amiga's multitasking works quite well, thank you. Why would you want to destroy it?
I read in another thread that Executive uses 8% more cpu cycles than AmigaOS.