Quick Add to Collection
It would be great to add an option in the quick adds, that allows you to add a card to existing folders in your collection. Currently, you can only "one click" to add to your general collection, but then have to go into your collection to edit and add to folder. The other option is to add with details, which then takes you into the card with a new page. If there was a third option to add to exisiting folders in your collection without having to be taken to a new page, it would be a much faster process when adding cards in bulk.
I did this using this script. It adds an "add card" button when I load a set checklist above the current "+ Collection" button that opens the full edit screen on top the current view. When the card is saved, that view closes and the current page/set checklist is reloaded with no search parameters in case you are adding multiple cards from the same set checklist. I hid the grading info so the card info to edit was vertically smaller (the add item button didn't require scrolling, though hitting enter works too). If you're so inclined, you could modify the script to hide more if you wanted.
It looks like this:
I also used this script to watch for me saving things on the "add card" page. It saves the price and date anytime I add a new card, then for the next hour pre-populates the form with those values. This is because I'm often adding multiple cards that I bought at the same time in bulk (boxes/packs/loosies), so those are just repetitive. There's also a button to clear both fields.