I've never used epoxy and I have little experience with boatbuilding but I know a thing or two about tightbond 3. I used to build laminated longbows and used tb3 to glue the laminations. I'm no engineer but my best guess is the compression and tension loads on a bow limb far surpass what a boat framing member would ever see before breaking. I never had a bow fail. I did switch to a 2 part glue but only because it increased the time available before the glue set up.
The bows were always dry though. Keeping them damp for a couple hours could change everything.