polybar-scripts VS polybar-vpn-controller

This doesn't directly answer your question, but probably has the pieces here for you to put together. I use this script for polybar using openweather API, there are a couple variations of this script in the repo too if you want more examples. Openweather API seems to work well though, you could probably modify it for you use case.

Yes, credits to the respective author. https://github.com/polybar/polybar-scripts/tree/master/polybar-scripts/easteregg-pornhub

https://github.com/polybar/polybar-scripts is a good resource for scripts, Google is a good resource for a lot of stuff. If you want simple see my dots I just show temp and conditions

I can offer this: polybar-scripts/battery-combined-udev

On a related note, there is a Github repo of common Polybar scripts (which is also available as an AUR package, polybar-scripts-git). It looks like you independently arrived at virtually the same script used for the updates-pacman-aurhelper module example.

Using the instructions from this site: https://github.com/polybar/polybar-scripts/tree/master/polybar-scripts/system-gpu-optimus

I do use Pipewire and this https://github.com/polybar/polybar-scripts/pull/320/commits/3cfaa589a2f22c5269d16732d035c9f0fee60ff3 for Polybar

The GUI is nice, the CLI is easy, and I also scripted a polybar module for it (that I probably should update... but it should work out of the box).

I never used Mullvad, but I know java applications won't work properly if you don't set environment variable for JVM, if it is a Java application this might work. Searching on google I also found this polybar module, that might be a workaround. Or maybe you can just use the cli.