I've noticed that in some cases people vote to close as Primarily Opinion Based when they think the only possible answer is "Up to the DM". There's a slight twist in this community where it's not always the opinion of the Asker; its often the opinion of the Dungeon Master / Game Master.
In those cases is the answer really "Primarily Opinion Based" or would the actual answer be, "You'll need to talk with your DM." Hopefully with some elaboration about possible rational they'll come up with and discussion.
Primarily Opinion Based stock definition reads:
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
Which is quite different from "Ask the DM"
However, if "Ask the DM/GM" is widely considered equivalent to "Primarily Opinion Based" on this community, than a slight adjustment to the close reason to indicate that could be beneficial. Or giving it its own custom close reason (space permitting).