https://mods.factorio.com/mod/upgradeable-quality
It upgrades nearly everything except belts.
Current workaround is to pull/replace the rings when they level, and name them only after they've reached legendary.
ring-teleporter-sprite, ring-teleporter-back, ring-teleporter-front, ring-teleporter-barrier, ring-teleporter
are all entities the mod uses, so adding these should prevent quality mod from breaking teleporters.
Because the quality upgrade also effects the teleport buffer, I'm inclined to leave it in place, so that it can level up. It just requires a mild adjustment to my strategy.