Fascinating. I've already renewed PM for next year on segments. I've well below the PM MQM threshold, but more than double the MQD threshold.
I try to purchase low fares, but it isn't always possible, so I've got a pretty good mix of fares in my 100+ flights so far this year. Scanning individual tickets... I had a a BHM-ATL-IAD o/w X fare where the first segment credited just $20. On the other hand, a o/w GRR-ATL A fare netted $534. Looking at other records, it's easy to see where those purchasing lower fares are going to struggle to meet the spending requirement.