Racing etiquette - pointing out power inconsistencies to other racers

Having used Zwift for a couple of years I’ve seen things unfold regarding treatment of Z power/Zada/requirements for HRMs, etc. However, my question regards people who use smart trainers that might be wholly inaccurate. Just did my first race in a while and was checking the segments; who had done well that day, etc. In short, I came across someone using a smart trainer, whose results were totally out of line with his real world riding. Looking at his ZwiftPower profile, this person is consistently winning A races (and working hard - posting really high heart rates). He has an open Strava profile and a few months ago tested his FTP on a Wattbike and came in at circa 2.3 w/k (which is commensurate with his IRL riding) now riding races at 4.3/4.6 w/k. I don’t think he’s deliberately cheating, but as he doesn’t ride with power IRL, perhaps doesn’t realise just how incongruous his numbers are. He’s clearly working really hard and enjoying winning races, do I mention this to him? More broadly, what the score on the accuracy of smart trainers. I’m fortunate enough to have a pretty accurate trainer (that I can cross-check with my power meter) are there big variations in smart trainer accuracy?

I don’t know if you should mention it to him or not, but there are indeed big variations in smart trainer accuracy. For example my Elite Qubo Digital Smart B+ trainer was showing an average power of about 4.3 W/kg, while my power meter is displaying about 2.8 W/kg. And there are many people using this trainer model that have the same problem: