From research I have done the temp reading on TPMS is really only measuring the air temp inside the tire. Rubber is a poor conductor of temp so that number is only a relative term. Having said that if one got a temp reading on one tire that is significantly higher than the other three, that would definitely be a red flag of a problem and could save the day. Since the OP stated when turning the brakes down to 2 the rims ran cooler, that would seem to pinpoint the issue is with the brakes rather than bearings.
2017 Lariat F-350 FX4, CC, SB, 6.7 PSD 4WD
2018 MONTY 3731FL, Residential Refer