Hmm that's a good question and one I've thought about. My understanding is that you can ask a place to wait and hold the offer while you finish interviewing, but they don't necessarily have to agree to it.
While the efforts to create a universal process are appreciated, many programs aren't following it. This fact puts the onus on students to pick up the pieces, which then makes me question the helpfulness of the universal process. AHhhh, hopefully this will be over soon.
Thanks for the reply! That's my understanding too... I'm just not sure how to go about it, or if it's risky. Ah well, I don't have any offers yet, but thinking about how best to handle that situation should it arise. It almost makes one miss the match (almost...!).