If the instructions say CA for the supplied hinges, they just might be right about that. If "the talk about foam safe CA" is in those instructions, that is worth following too.

I don't know of any ARF that has provided CA hinges and then wants them installed with epoxy. Matter of fact, have you ever seen that done anywhere? But you have a sensible observation. And ARF manufacturers really haven't shown perfect understanding of our hobby. They make beautiful and for the most part well made stuff, but almost always have one or two flaws in their work.

Foam wings usually have sufficiently deep wood TEs. Foam won't hold hinges that are epoxied in any better than it would hold CA hinges, whether or not the foam stood up to CA. So most wings with foam cores have decent trailing edges.

What to do? Find out how deep your TEs are. Or buy some foam safe CA. Or better..................

Buy some good quality plastic hinges like Dubro makes and use Hinge Glue. Darned if this new hinge glue makes gluing in "real hinges" a snap. It's as easy as doing CA hinges, and almost as fast. And it holds the hinge to the TE like epoxy without ANY of the fuss and bother epoxying in hinges give us. So the hinge will be anchored as strongly as the TE is going to provide, CA hinge or not.

What is the model? ARF???

BTW, my preferred method for most is a good quality CA hinge if good quality came with the ARF. But I almost always use one Dubro hinge in the rudder if it's carrying a tail wheel load even if I'm using CA hinges everywhere else. And truth is, using Dubros with hinge glue is so bloody easy and bulletproof that the really good ARFs I know will be around awhile get their CA hinges swapped out for the plastic. Hinge glue is awesome stuff. And the good quality plastic hinges have been awesome from day one, just a real pita to epoxy in. New technology really is good stuff sometimes.