+1
the UI could be improved (I always end up hovering for tooltips on controls) but it works really well.
I also like that tabs will stay in the stash by default on close, so its great for opening a bunch of reference sites really quickly without worrying about losing them
Closest thing to the old firefox experiment from a few years back.
https://whatpwacando.today/ is a nice site to test things out. You should see the option to install on Firefox for android, as well as verify what features work.
Glad it finally landed in main, I've been using nightly to install PWA's for a while. It worked fine, but having the two different browsers to juggle for initial install was a pain.