I think either route is viable. They could go into the heightmap ESPs (seems perfectly reasonable to me) or Onra and co. could provide them in separate ESPs. It's not as if NOT including them in the heightmap ESPs would prevent Onra and co. from producing them at all. Personally I like as few ESPs as possible, so would be in favour of them being included (especially since it allows other modders to reference such locations for quests in their own mods without needing ANY further effort than they've already made to be able to use the heightmap ESPs in the first place).

Post Limit.