I couldn't get it to work at first, which was frustrating, but after some tinkering with Flatseal to see if it was a permissions issue, I eventually solved the issue by enabling it access to "All user files"/the home directory, which is where Steam is located. Once I enabled that, it worked perfectly. Hope this hotfix and review helps someone else too

Works amazingly! (I only tested on non-steam games)

Test popups work, but actually trying to "boop" something does nothing. Following the provided troubleshooting steps did nothing.