[update 2017-10-05]
It now has the option to toggle active mode using the menu/mouse, so I'm satisfied with that. Thanks for the quick update! My only other minor quabble is that things don't seem to highlight the way they did in 1.x - e.g. a horizontal bar (my niche need) doesn't highlight at all, but I was still able to delete it.
[end update]

This has been a go-to add-on for years, but the new version has some usability issues (aside from those forced by Firefox).

If you use the Firefox setting where typing results in a text search, the Activate Nuke option by key doesn't work. This means I'm limited to the "Remove this object" option, which no longer highlights the object to be removed.

I use Nuke to help minimize content before creating a PDF, and sometimes need very specific things removed where the mouse has to be at exactly the right spot (like removing horizontal bars). The highlighting made that possible. Now, I have to try/fail/try repeat, and it's not good.

Perhaps if the Activate Nuke could be toggled by mouse instead of keystroke, or by menu icon like Page Eraser on Chrome.