I'll go out on a limb and say Tom doesn't build Maxwell greens because they have already been done......basically, he doesn't want to.
Besides, he has always said his models are the more subtle Scottish greens, not American greens, no matter how good.
Years ago, I did an MP for a Press Maxwell course, and actually even talked to him on the phone once. He did admit (as Chris Clouser chronicles in his book) that his father was better at green building. But, in essence, they both built what he called a series of "one mounders, two mounders, three mounders, and the occaisional four mounders. He was kind of like Raynor to Mac, not doing a whole lot new, just applying his fathers ideas, but still.......the concept for even Perry M greens was almost as formulaic as RTJ, Dye, me or almost anyone else.
On a deeper level, I would suspect that with his low budgets, Maxwell really did figure he had to defend mostly at the green, which probably cost the same any way he built them while adding bunkers did add cost. Tom doesn't really have the budget problem, either.