Firefox's extensions actually let developers do stuff, so we have tons of tab groups extensions. My favorite is Simple Tab Groups. But if you dont like that one, you can swap it out for a different one! DO YOU GET THAT KIND OF CUSTOMIZATION IN EDGE?
For rust specifically, I recommend checking out NoBoilerplate on YouTube. His videos are short, sweet and to the point, and they make you feel better about the progress you're making. Also, LetsGetRusty is nice for when you are first going through the Rust Book, because he explains everything with examples
If you really want to tripleboot Linux, I highly recommend systemd-boot, especially because you are already using Arch, which supports it. I'm sure you could get it to work with Pop.
Some guy made a calculator in pure css