Some guys build to fly, some build to crash. The guys who build to fly use CA and keep it light. Firewalls, 30 minute epoxy, but just enough. The guys who build to crash (that is, fear of crashing), use epoxy, screws, fillets, etc. ostensibly for added strength. When you build to crash, you fulfill your own prophecy. The extra weight is just that -- it doesn't do anything extra except make your plane heavy -- and when it does crash ever notice all that epoxy didn't do a darn thing for you? You are still picking up pieces. Just opinion of course.

By the way, regular CA works just fine on most of the foam planes I've seen coming out now. Test a spot, you might be surprised before you spend 3X on 'foam safe'.