Create new version when going back to old version
Make it so that it automatically saves a new version or prompts you to save a new version when you go back to an old version. I just lost several hours of work because I went back to check something in an old version and forgot to create a new one before I did...

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David Simons (Adobe) commented
It actually does do this already, but apparently not in a clear enough way, sorry!
Check out the hamburger menu in the History panel (next to the name of the tab), and enable Show Auto-saved Versions. A recent one will say something like "HISTORY_STATE_YOU_CLICKED + 700 redos". Click on that and you'll then see the state of the history when you originally rewound to that place. You can then click on any of those 700 redoable things lower down in the History panel (you probably want to click on the very last one to get back to where you were).
The other way to do this is to manually hit Save before jumping back in time, then you can click on that saved state to get back.