This thing is great. One piece of feedback is maybe let us have a toggle to have this addon snap to the bottom like where the vanilla Find feature is located. The toggle would still allow people to have it on left like it is now. Is this extension acting as a sidebar? I guess that could explain why it snaps to left...

Even better when you replace CTRL+F (and even F3), which this does not do by default. You can do this in AHK v1 with this script:

#IfWinActive ahk_exe firefox.exe
Ctrl & F::
SendInput {Ctrl down}{shift down}{F9 down}{Ctrl up}{shift up}{F9 up}
return

#IfWinActive ahk_exe firefox.exe
F3::
SendInput {Ctrl down}{shift down}{F9 down}{Ctrl up}{shift up}{F9 up}
return