Not all epoxies are created equal. I absolutely refuse to use some of them on any part of my bows. Don't use the cheap, dept. store, 5 min. epoxy. I use Smooth On a lot and never have issues.
Next important is surface preparation. With epoxy, the glueing surfaces should be perfectly mated, and then adequately roughened so that the glue joint is not starved of glue as it's held or clamped together.
Then, ensure the surfaces are free of oils or grease from hands, tools, and such. If there's any doubt, degrease with denatured alcohol or something similar.
I think these things are more important than whether or not the area 'works' a wee bit as the bow is drawn. If good gluing methods are used, a glue joint can bend and not fail, even at the handle. On the other hand, if good gluing practices are NOT used, it may fail even if the area doesn't bend a noticeable amount.