increase explorable spawn rate

[VanillaPudding]

With a much larger average play count these are getting devoured swiftly. Would it be possible to increase their spawn rate and / or instance them somehow like quests?

Like, maybe they can hit the journal and you get the same type of tool as a quest, then would need to invite friends to your "instance" of it before they enter. (slightly tedious, maybe another clever way from someone smarter than me)