Updates: more solid kickstand joint, moved slider for convenience, and added a part for better fit against the switch.
Assembly Instructions: pop out the Nintendo Switch's kickstand by rotating it past its limit. Next, insert the part that looks like the kickstand. Put the slider that holds the video games into the gap on the main body part. Press the main body onto the back of the switch, lining up the pegs on both the main body and the kickstand insert. Finally, the backpack's kickstand should be popped in so that the bevel on the side matches with the main body.
Snap fit, shouldn't come loose, though your machine may vary.
Holds up to 5 games, and has a much more solid kickstand than the built-in one.
The kickstand should stop at the angle shown. If it is too tight or too loose, scale the kickstand +-1mm, the difference seems to be by material (ABS vs PLA). The files are for ABS, so if using PLA, you might need to scale the kickstand down.
This part was made on the uPrint SE Plus.
Edit: fixed issue where the thumb slider on the cartridge holder actually wouldn't let you insert the last game. You'd think I would have seen that at some point, but apparently I only own 4 cartridges.