So you are saying instead of flying AAA-CCC or CCC-AAA, on 10 occasions you flew AAA-BBB or BBB-AAA, which in distance is 110 miles longer than flying between AAA-CCC direct?
If this is the case, you would you also have earned 10 X 110 (1100) extra PQMs besides the 5,000 PQMs from the 10 500 mile minimum PQM segments between BBB-CCC ?
Are the AAA-BBB-CCC routes published, or do you have to construct them with multi-city?
Yes, they are published routings, which come up immediately after the non-stop alternative (but, on the rare occasion they don't, you can construct it with multi-city). The whole process adds about 3hr 30min onto what would be an 11hr non-stop. I take the view that the day is ruined anyways and the ability to upgrade to C on the eastbound overnighter with reasonable reliability makes it worthwhile. When in Y on the westbound, it's often less crowded so a free middle seat is a good expectation. All of these factors make it worthwhile.