Are you allowed to use 2 different thicknesses of plastic on your robot? Assuming that they would all be able to be cut from a sheet of 12x24 if they were the same thickness. And what about using abs and polycarbonate on the same robot? Is the rule saying that they have to be able to be cut from the same sheet of plastic just referring to size or thickness and material too?
Posting this on the Official Q&A would get you a better answer, as we are not the GDC, you the GDC answers on the official Q&A.
Here’s an unofficial answer based on previous years Q&A’s, many years as an inspector, and common sense: if I were inspecting, what you are proposing would all be legal (different thicknesses and different types of plastics, with all pieces able to be cut from a single 12” x 24” area. If you have a lot of complex pieces that would make it difficult for an inspector to measure, you could prepare for inspection by having a measured drawing showing all the pieces arranged into a 12” x 24” area.
But, if you have the 3+ weeks to wait for an answer, it would certainly be in line to have your mentor post this question on the Q&A.
I believe this statement is to be false - there is no commercially available single sheet of plastic that provides multiple thicknesses.
I would put it in Q&A if you are considering this approach.
Karthic answered the “two different types of plastic” in the NbN seaseon: Answered: Different materials within plastic sheet size limit
and he answered the “two thicnesses of plastic” in the Skyrise season here: Answered: Legal Plastics Thickness?
While Q&A answeres do not automatically transfer each season, it seems reasonable that the ruling would still be the same if answered again this season.
Hopefully, it will be included in future games - I think this question comes up frequently enough.