There can be a big surprise when a decent USCF master [2350 or so] plays correspondence. I remember one just starting playing correpondence and was expecting to do well. I beat him in about 8 or 9 moves and he then withdrew from the correspondence tourament.
[ He tried again later and then his over the board and correspondence chess ratings were similar.]
Maybe so, but you're still playing against a stacked deck. As I said in the posts you quoted, I personally know of players that top the USCF CC charts that are 100% guaranteed using computer assistance. As such, you're often going to lose to new players that are also using computer assistance. I'd rather not worry about it to begin with by either:
A - Only playing with friends I can trust.
B - Playing on a level field where my rating isn't trumped by someone breaking the rules.
I don't understand how you know that the top rated players use engines in USCF CC events. Then I also don't understand why they don't do anything about it, since in chess.com there are endless lists of people whose accounts are closed because they cheated.