This is a small Gridfinity Window with 4 Holds. In all Holds you can put an Storage Element where you can choose from 3 Different.

1: Blaze Evercade Cartridge (stores 3 Blaze Evercade Cartridges)
2: Nintendo® DS/2DS/3DS Cartridges 
3: Nintendo® Switch/Switch 2 Cartridges

The second and last aren't finished yet but I'm working on it. If you have Ideas for my Project share them in the comments.
I had no Time yet to print it and test it out, that's why I'm just having CAD Pictures.