[MJGrzymek]

I was just thinking about how it's an underrated open problem which pairs of (number of variables, degree) are undecidable for MRDP.

Correct me if I'm wrong but I think it's guaranteed to have a finite answer, as a list of the minimal undecidable pairs. You can even throw in maximum absolute value of coefficients, though if you limit all three things that's decidable by being finite.