Morrison with kudu tip.
Silvertip with rough sheep horn tip.
I have, and have had, a significant number of bows with horn or antler overlays on the tips. Not one of my bows has ever "shed" a tip or had a problem. Worth noting that all of these bows were built by bowyers with many years experience, and they liked working with horn and antler materials.
I don't know the exact procedure for adding overlays but I'd say the correct adhesive is paramount. I'm guessing of course, but a non-brittle adhesive would seem essential. Degreasing and cleaning the surfaces has to be performed. Seeing that horn and antler are porous, I would assume a final moisture-proof finish is required. I've always used rubber tip protectors on my bows to preserve the finish and keep moisture out of the laminations.