That's essentially what I'm doing. I did it with carbon laminate and that broke out quickly, simply not enough material. I'll probably add some milled fibers along with graphite and do a straight 2-part epoxy, either Resin Research or Pro-Set. The hobby grade epoxies aren't great and resin research is very inexpensive per quart (though it takes a week or 2 to ship usually).

My boards have gelcoat all the way to the TE, but I'm not going for looks more for hydrodynamics. Might suggest spraying a clear lacquer post repair, just to keep the epoxy from yellowing.

Any tips for fixing dinged tips? Looks like a lot of epoxy+milled fibers in that area and much more difficult to shape. It'd be easy if Nacra just sent me the molds...