Rated 5 out of 5 stars
Any chance we'll see regex search in a future release?This review is for a previous version of the add-on (1).
Very doubtful. It's not in the scope of this add-on I think, plus I wouldn't know where to start to implement something like that, as, currently, FBT doesn't mess anywhere with Firefox's find feature.
You could try https://addons.mozilla.org/en-US/firefox/addon/fastest-search/?src=search , I made a quick test and both add-ons seem to work correctly together (although I have no idea how that add-on works, I couldn't even find its regex feature, but it claims to have one).