Idk if it’s intended since the normal rate button was replaced with the one for the jam, but the URL https://millerdark.itch.io/under-one-sky/rate?source=game still works so even if people can’t rate the game for the Jump Ship Jam unless they have submitted a game themselves to it everyone with an itch account can rate the game in general
(btw you can check that a game’s rating page routing is formatted like that by opening another game’s rating page in another tab and looking at that URL, just make sure that game is not in a jam too; it’s important to open in another tab because otherwise the rating pop-up in the game page opens, and that doesn’t change the URL)