To my knowledge PMI did not engage in any of those subprime pool deals like RDN and MTG, at least I have not seen their name in any SEC filings on deals like RDN and MTG did. They did provide primary coverage on subprime, of course.
All of PMI's "pool" deals (or substantially all) were these modified pool deals that were done with the GSEs from what I can tell. They have some really old pool deals from the 90s that they disclose in their filings, but these are immaterial.
And yes, it is striking the difference in reserving between a company that has no incentive but to be honest, and another that, well, let's just say they have an incentive to minimize reserves at this point.
But regardless of where the reserves are, the economics can't be avoided forever - sooner or later those losses will need to be paid.