A remix of Thunderthestorm3's and Kulmadate's designs, I found them a little tough to remove and the Joycon one could be pushed on far enough that the stick would be able to tilt again, the ears I've added on the open end help with removal and the ear on the closed end helps to stabilize even when the it's inserted fully.
For the Xbox design I wanted to be able to print without supports.

Each model is oriented upside-down for best printing, so when you go to use it make sure the print bed side is facing you.

The Xbox stabilizer currently has a small protruding cylinder which marks the bottom (facing the controller), I'm trying to come up with a better way to signify since both sides look similar!