Same here, I tried the PWAsForFirefox extension a few years back and found the setup to be too much of a pain in the ass compared to the Chromium forks. I tried again around 9-12 months ago when Manifest V3 drama was making the rounds and found the extension had been overhauled and that’s no longer a problem. As a bonus each PWA is a self-contained browser instance, so performance is improved when only the PWA is open, and extensions are per-PWA. So I can run only Purple Adblock on my Twitch PWA, or only uBlock for Youtube, etc.