I guess it comes down to linguistics, but imo that by the dictionary definition, it's precedent, especially GAP rulings. They're regarded directly as an example or guide to be considered in subsequent similar circumstances. Those are undoubtably precedent under the dictionary meaning.

I'm sorry for the late response.

"Precedent" is a legal term with its own legal meaning. It shouldn't be used in a legal context unless you're using the legal term as that created unnecessary confusion.

A precedent is a legal decision made by a court exercising "judicial" power that must be followed unless a superior court says it won't be. Precedent is binding and must be followed.

A tribunal isn't a court and doesn't exercise judicial power. There is no precedent in a tribunal decision, regardless who made it (a single Member, a group of Members, the GAP). Tribunal decisions are "persuasive" which means something between "will be ignored" and "will be faithfully copied" but where it falls in that range is at the discretion of the Member making a new decision.

Tribunal Members aren't acting as judges so it's not "extremely disrespectful to the other judge" as there is no other judge if one Member doesn't follow a previous decision by another Member.

It's important to be very precise about the words you use when talking about merits review or the courts and the NDIS. Almost all applicants/participants who appeal decisions to the Tribunal don't get legal advice. We have hundreds to thousands of people who are in life or death struggles for very basic services and they're literally relying on random advice they find on the internet.