Vlad Using Orion 0.99.120.1-beta & Tridactyl 1.22.1:
Pressing 'f' does bring up link hints, as expected, but they are not styled correctly. They are simply black text on a transparent background, which makes them very hard to see.
Pressing 't' or 'b', etc. to invoke functions such as 'open new tab' or 'show bookmarks' invokes the 'ex' command line instead of invoking those functions.