Can't change Gear Lever's default AppImage location
This one I already have a solution, I'm just posting this for folks who might stumble upon this problem. When trying to change Gear Lever's AppImage destination folder, literally nothing happens, it throws a silent error to the terminal. The contained message is 'The folder must be in your home directory', so my initial guess was that it didn't consider /var/home/$USER (where the file chooser starts) to be a valid home directory. Sure enough, after analysing the source code, the only checked path is /home/$USER.
I've also opened an issue at Gear Lever's repo: https://github.com/mijorus/gearlever/issues/89
I've also opened an issue at Gear Lever's repo: https://github.com/mijorus/gearlever/issues/89
Solution
As for the solution, just follow the path you would initially, but starting at /home instead of /var/home
