If they are made by cutting a ring shape out of wood, the grain is too weak for long term wear.
I more common method for wooden rings is to cut a long thin rip at 1/16th”. Soak it water for 30 minutes. Wrap it around something finger size, put a rubber band around it and let it dry. You can get a good imitation of a glossy epoxy finish with CA/super glue. This gives a lot more strength than a cutout.
I don't think that is true- I build and restore both wooden and fiberglass boats with epoxy, and have used it in almost every possible way. There are different thicknesses of epoxy with different properties, but the ones specially designed for penetrating deeply into wood - such as clear penetrating epoxy sealer will indeed penetrate extremely deep into wood, the manufacturer claims 9-16". In practice, almost any epoxy will penetrate at least 1" into wood.
If anything, epoxy often has too much penetration, and I end up doing a first coat or two that disappear fully into the wood, and another thickened one so it actually stays on the surface or joint.
I more common method for wooden rings is to cut a long thin rip at 1/16th”. Soak it water for 30 minutes. Wrap it around something finger size, put a rubber band around it and let it dry. You can get a good imitation of a glossy epoxy finish with CA/super glue. This gives a lot more strength than a cutout.