Follow list relationship is a bit different. You’re saying, I want to see your stuff. A priority follow is more of “I really don’t want to miss whatever you announce”. What you might call a subscription. I think nostr could solve this with priority DMs, but you need to have a tool for creators to make lists quickly and easily and be able to bulk dm the people who opted in to be on those lists. In kind 1 clients I imagine this as a subscribe button and a priority dm area. In specialized clients you might be able to opt into different lists and creator can categorize which list you belong to. This is mostly a front end function and a way to sort who should be priority dmed and who shouldn’t.