Welcome to this week's "Premiere updates that broke something which worked perfectly":
I used to be able to select a bunch of clips in my timeline > Right click or KeyboardShortcut > Set To Frame Size. This would make 4K clips (for example) in my 1080p sequence shrink so they say "50%" in Effect Controls...perfect for most of the clips, except the ones I want to crop into (up to 200% losslessly, thanks to them being 4K. This is literally the main benefit of 4K workflows).
Now the ability to 'undo' the Set To Frame Size is GONE. Yet somehow we have a THIRD option now.. How did this get so complicated and yet somehow completely remove the main feature we needed?
There's no way to untick Set To Frame Size (sorry - just checked and it's actually renamed now to Fit To Frame, by which Adobe meant 'Shrink To Frame' because there's now a 'Fill To Frame' which means 'Expand To Frame' and the third option is 'Scale To Frame Size'...oh my gosh.... what a mess.)
Please just return everything to how it was. It was perfect before. With just 2 options. Or at LEAST make Shrink To Frame Size a toggle/ ticked or unticked thing in the menu like it used to be, so I don't have to individually go through tons of clips I shrunk in my sequence and manually go to Effect Controls and one by one type into the Scale field "100%" for all the ones I want to return to original size... Aurgh.