same here - Quixel Bridge not avail in editor (installed on arch through the zip file - v5.0.3)
when looking at vault (through lutris) I can see the plugin in the vault but cannot attach to any engine (since the installed engine is not know to the lutris-launcher-version).
To use Quixel Bridge in the editor on Linux, you’ll need to build it from source. It’s not included in the binary releases for now, unfortunately. Hopefully it will be in 5.1.0