I just gave it a try on my Modact 3 4.10.1 installation but unfortunately went into a 60% (=missing FM) CTD. Putting the buttons from the F-8F in place doesn't work either since then other FMs from the SAS buttons are missing.
I'd tend to say that if the F-8F refers to the Sea Fury or Corsair FM, there seems to be some naming issue. Otherwise, if it already has it's own FM, it might be adviseable to use and/or include DiffFM into the test package.
Best regards - Mike