If its not THROUGH the threads, its fine. Epoxy is strong, but brittle, it will flake off, and, possibly poke through...
I would have used something flexible. RTV, or something. Even just spreading rubber cement (patch kit stuff) over it would have kept the threads covered.
Put it on the rear, and keep an eye on it. If it looks like the threads are fraying worse and worse, just get a new tire. I'd rather spend $40 on a new tire than have a blowout cause me to lose control. But right now, it looks OK to me
