If you can build in one thing, I'd pick something equivalent to Omnisearch. That makes it much easier to find things. I always struggle with the default search.
- profiles have no indicator on the taskbar so it isn't easy to see which is which when using multiple profiles at the same time (I don't want to have to use multiple Firefox versions just to know which profile is which on the taskbar).
- when clicking an external link in another app I want it to open in whichever profile I used last, like chromium browsers
- No pwa's (I don't want to use an external app)
- Compact mode being unsupported (when watching media a pwa shows the biggest video view, Firefox non compact the least)
- Ads being incorporated
- Ads for Mozilla products
Things I like - uBO
- Recommended extensions so I can have some faith they are checked to be legit.
Firefox just feels like a browser stuck in the past.