I can't say whether it's an official policy, but I know for a fact that Ross puts emphasis on recent work. So say you have like a 2.0-2.5 from undergrad and then 1 or 2 years of DIY post-bac with a 3.8-4.0, that's usually enough for them to practically ignore the undergrad grades. That said, AACOMAS (the DO application) does grade replacement and verifies it, and as you mentioned SGU does it as well, so obviously try those apps first.