I'm wondering if you have considered adding support for equations and tables by transparently invoking eqn and tbl from src2man.
From time to time, I see manpages with beautiful ASCII math and ASCII tables on them, and I'd like to be able to make use of that in the manpages for my C code documentation as well.
Ideally, this would work for PDF output too, because eqn and tbl can be processed into nice-looking PS output IIRC.