Yes, Mull browser, like Fennec (for Android) has telemetry disabled and supports extensions, but not Alby. Not sure yet the difference between Mull and Fennec but Mull may be a little more locked down (stricter privacy)
Discussion
do either of those have the nag on disabling widevine disabled???
I havent seen that nag
can you see spotify link previews? https://openspotify.com
That link has malware
it was a typo, i forgot the . open.spotify.com that has malware too, called DRM, that is already in your browser. my browser doesn't show them because i have disabled it. but firefox browsers show a nag persistently begging you to enable it.
sorry. https://open.spotify.com