Thanks to Oow for a brilliant original design (https://www.printables.com/model/1398755-a-place-for-all-my-books-board-game-insertorganise). All I did with my remix was trim off some of the excess filament that wasn't needed but still kept all of the original functionality. It still works for premium sleeved cards and supports vertical storage with the playmats in the box as shown.
Print 4 of the player files, and 1 of everything else.
My print in the photos is hashed as I print without tops/bottoms/walls to save on filament. Though it's one of the very few inserts I've ever printed in actual players colours and it does look really cute.
The author remixed this model.
Removed parts of the original design to speed printing and reduce filament without losing functionality.