I recommend adding Flathub to your Flatpak remotes if not done already it's basically required to have access to most applications a normal desktop user would want.
Let me know if you run into any problems using it.
If there's an API for Mullvad, it shouldn't be difficult to adapt the code on this or create a version for it.
The "client" does little work, TBH, just get the list of server and hand the data to Network Manager :)
Thank you for the good work!
I'm so happy to find something useful that I need in CL, I'll try it asap.
Btw, It would be great to create something similar for mullvad as they offer only rpm and deb like NordVPN.