I remember creating different extension sets using the built-in Extension Manager and the third-party tool Conflict Catcher. I had sets for gaming, video editing, and normal usage. It was a simple matter of selecting the correct set and rebooting. Or you could hit shift on startup and start into a minimal system without any extensions.

There's a good reason the third-party extension manager was called "Conflict Catcher," but the power and flexibility such a system grants users is unmatched.