The "max psi" we're speaking of is not a red line. It is not the absolute maximum pressure a shotgun can withstand. It is the recommended "maximum average service pressure"....meaning a modern 12ga in good condition is intended/expected to digest 11,500 psi loads day, in-day out, every day, year in, year-out, every year for tens of thousands of rounds. The gun will eventually wear out, but it won't fail catastrophically from SAAMI-max loads. That's the reason it's not difficult to find published data for loads averaging 11,000 psi.
I never hesitate to withhold information from people if I've reason to suspect they could benefit from it. I think it's best that people be educated. I certainly appreciate it when others point out that I might be laboring under a misconception and help me to understand why limits and boundaries exist. I find that, when we understand the reasoning behind "rules," we're more willing and likely to play the rules.
I don't advise anyone to assemble any load for which pressure data does not exist. And if they wish to hold themselves to some arbitrary pressure level below 11,500 psi, that's perfectly fine, too. OTOH, I'll occasionally suggest there's no reason to shy away from loads with published pressures in the 11,000-11,500 psi range.
That said, I don't wish to discuss the meaning of the values in the two columns to the right of the MAP column.