What could possibly go wrong?!!, and... how hard can it be?

I'm contemplating bolting a LF foil to a 2011 12'6" Fanatic Falcon.
All views, ideas, opinions, advice, suggestions welcome, including the smirks

Other useful information like how far back to mount the foil and should I lop the last 2'6" off the blunt end of the board could be valuable.

Who else has had a DIY experiment? what happened?