Good old RTFM... But:
All I wanted to do is correct a typo in the title of a snapshot. As a Mac user for decades now, pressing modifier keys is what I always try first if I want something special. I didn't modifier-click on the list, because this list is meant to choose one of the snapshots, something you do every day. If you want to save something new, or some change, the first thing you do is click the Save button above the list. But once you're in the Save dialog modifier-clicking doesn't work any longer. My point: the UI is a bit misleading here.