I have an entire foam wall with plants and branches in it without using the silicone or fiber. I free roam crickets all the time and they are never that interested in the foam, the roaches climb around it sometimes, but the crickets mainly stay to the top screen. The ones that do go on the foam quickly go back to the screen. Our cham's eyesight seems so good that they find them in no time anyway. I've only had a couple crickets ever seem to get lost in his cage, but never saw them chew the foam or cause any problems.
I actually like the plain black foam look, but when i build another one i'm going to try sculpting the foam and using the silicone/fiber to see how it turns out. I suggest using egg crate(light diffuser) to mount your pots/branches/etc on that you're foaming and foam over that. Then just secure that to the dragon ledges for easy removal.