Edit: while waiting for your replies, my PAM lockout/timeout reset and I was able to try. It worked. 🤣
I am trying to open the cloud provider Internxt’s desktop app. I have Librewolf installed, which I’m sure is going to work as a substitute for Firefox. Can I
ln -s /usr/bin/librewolf /usr/bin/firefox
to make their app use Librewolf instead, thinking it’s actually executing Firefox? If not, would an alias work?


Exactly. I’ve found xdg’s script with a switch case cumbersone with my custom script (and ugly), while the other stuff is good enough for open-with. So i just “wire” the defaults, while keeping to a naming scheme.