You can quicksave whenever you want and load it whenever you want. If you are running No Save Load Assist you can't do this to give you an advantage in anyway like saveglitching.

Wouldn't that be sv_cheats 1?

That is not allowed in the rules. There is a trigger to activate her voice near the end of the walkway that is near the elevator. You have to walk towards the angled platform then when you trigger it you can go into the elevator.

Is under elevator in chamber 9 allowed in legacy? Thank you very much!

For Legacy are tricks like portal bumping and peeking allowed? I didn't notice anything in the Legacy rules about this but wasn't sure.

I was running on the steam version for a while because I didn't know that the source unpack version existed or how it worked. I did fine using that but once I started using source unpack a lot of the different glitches and things became more consistent.