[struanr]

I use this; it does require changing the Firefox accelKey to something other than control, but works well. I also tried using nyxt but found it to be far too slow.

[bovine3dom]

You can patch Firefox (no rebuild required) to not reserve keys if you'd rather. Discussion here [1] and convenient AUR script here [2].

[1]: https://github.com/glacambre/firefox-patches/issues/1

[2]: https://aur.archlinux.org/packages/firefox-no-reserved-keys-...