Well, honestly I don't have a ton of experience with the stuff. Most guys i know that have used it, swear by it...
In some applications, they're glueing whole panels on.. But I'm kinda oldschool and am leary.. and will always prefer welding...
I would think if you could get the panel to fit up decent, find a way to clamp or screw it into place properly it would hold fine for many moons.. The biggest issue other than proper edge-prep for adhesion I think is getting the patch flush everywhere while the stuff dries...
I'd also wanna throw some Dyna-Glass over the seams fo sure..
It definitely dries much different than 5200, not nearly as rubbery, much harder...