

I’ve been using IronFox since it came out and I don’t think it has been out for 2 years yet… are you thinking of Mull from which it was forked when DivestOS stop being maintained?
Also, I’ve been using Librewolf since its early days too, and their updates are always only 1 to 2 days behind an updated Firefox. I know cuz ai update daily on my Artix Linux machine and have both browsers. Whenever Firefox is updated its usually the same day or a day later that Librewolf is also updated to the same version number.
I get the concern, but honestly the Librewolf devs have proven themselves at keeping pace with the upstream for quite a few years now. Hopefully the Ironfox devs can do the same.
Just use LibRedirect extension to redirect to an invidious instance. Take the URL of the video you want to watch and download the video using yt-dlp. Watch it on your desktop using mpv.
On Android, use Newpipe or Tubular Fork of Newpipe to download video. Better yet, use Seal with Sponsorblock flags to download and watch without sponsor mentions. Watch using mpv.
On iOS, use Brave browser…