Tridactyl is nowhere near as usable as Pentadactyl was, and its injection of JS/CSS in every page you visit is very, very intrusive. Sadly it's the only option that is usable for me at the moment, but I think everyone - including its devs - would agree that it can never reach the same level to Pentadactyl due to not having access to the browser's chrome.
About five years ago we had agreement in principle with Mozilla to extend the web extension API to accept keypresses from anywhere, provided that someone did the work to write that API.
We started it [1] but lost interest because we think Tridactyl works mostly fine without it (press ctrl+, anywhere to get back to Tridactyl) and I have always found more urgent things to improve.
I'd be happy to help anyone who wanted to pick it up, but a lot of the political work of persuading Mozilla that such an API would be useful would need to be restarted since most of the people we persuaded in the past have now left Mozilla.
