So for All Cases, I've noticed that the current runners wait during the credit scenes before continuing the run as normal, while this makes sense, would it be allowed so that after the final objection on Turnabout Goodbyes you could just exit out of the game and relaunch it to start Rise from the Ashes? It would save several minutes of waiting and make the run a bit shorter.

I doubt there's anything against resetting, but I doubt I'd be the person to judge it.

A problem with this is that the game doesn't count Turnabout Goodbyes as complete and unlock Rise from the Ashes unless you sit through the entire credits sequence, despite the IL rules ending the run at the last objection. This would in a way be somewhat equivalent to exiting the game prematurely and loading a save file from later on. That said, this is a NG+ category and so Rise from the Ashes will be unlocked regardless.

I'd say it's questionable, but it definitely also depends on what others think of the matter.