Well - time to start calling folks. I replaced all 4 in December 2020 and put about 4-5K on them. We had a near miss on our Sept trip, when we stopped for evening in SC, found the following (still was at full 110 psi). Just checked the date codes, the failure was a 3620, have 1 more of same and 2@3520. My replacement was a 5120.
Link to the recall acknowledgement -
https://static.nhtsa.gov/odi/rcl/202...1T018-9830.pdf