Could wrapping versus not wrapping account for some of the temperature difference? (along the lines of 185 unwrapped could be roughly equivalent to 190 wrapped?). I heard the 185F thing too. On my last brisket, I had to cut off a lot more hard fat than usual. I didn't foil, and it took much longer than expected to get up to 185, so I checked for tenderness at 185 and decided that it was ready. I'm only at roughly the intermediate stage on my brisket learning curve, so I could have gotten it wrong, but it was very tender in the thick middle, and the result was one of my better ones.
18.5 WSM, 22.5 WSM, Weber 22.5 OTG, CyberQ WiFi