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4 browsers that will continue to support uBlock Origin and other ad blockers with Manifest V2
(www.xda-developers.com)
This is a most excellent place for technology news and articles.
You could also just stop using sites that don't work in Firefox. Also https://webcompat.com/
Absolutely.
And casually, that's exactly what I do. To be honest, casually I haven't encountered any (I don't think...).
But for work stuff, sometimes I don't have a choice. I guess I'm just thankful it doesn't require edge IE compat mode, or even IE itself