Confirmed that AT&T is running dedicated n5 here, at 10 MHz, by process of elimination. LTE is 10x10, and H+ is 5x5. They might be running DSS or n2 or n66 but I kinda doubt it. Guessing they aren't running H+ on every site anymore either; signal appeared a good bit weaker than the B5 LTE signal when I band selected to it.
Also, B14 is pretty obviously not on every site here; signal levels at my place are comparable to B2 and, well, 700 should be a lot better than that. Explains why I wasn't seeing B14 aggregated normally. Though apparently they have 25 MHz of B66...one 15 MHz carrier, one 10 MHz.