I don't know what you mean by APA.
In the U.S., there are only a small handful of drug-tested federations, and the large majority are not tested. Of the tested federations, only one does OOC testing and is WADA compliant, and that is the USAPL. There is a certain prestige to competing internationally in the IPF through the USAPL, but no financil incentive, and there are better financiap opportunities in untested powerlifting.
Long story short: there is very little incentive specifically in powerlifting to compete internationally through the USAPL and evade drug tests. Yes, people have done this before, but very few do so in powerlifting in the U.S. because there are so many options. Of those that use in the USAPL, the large majority of offenders are not on the international teams, and I can't remember anyone outside of Jesse Norris (for a stimulant) who tested positive and lost an international spot.
It is equally as impractical to think someone would bother trying to cheat the tests in the U.S. as it would be to think an 18-year-old girl can be as strong as she is naturally.
Sorry, I didn't answer for a couple of days because I know you were going to write some huge block of text and I just couldn't bring myself to have to read it. Maybe this would make more sense if you were a part of U.S. powerlifting.