Changing the presets wont lose your changes to that EQ. Is that right?

Nope.

I just tried it on my Mk1, and the behavior is exactly as I described it in the first post: If you hit "save", it's permanently saved. If you don't hit "save", you lose your changes as soon as you switch presets.

You will also lose changes after a power cycle unless you hit "save".

___________
Tony Fabris