so no mention of TM-AC1900 on that page then. someone could add that in a sentence in bold, because most just read/look for ac1900 and assume it's all good. When I first flashed merlin on mine, I didn't even check the supported devices list, I just went off by others saying that's what they did to their TM-AC1900s. So I think that's where the confusion all started.RT-AC1900 is supported , a TM1900 (a TMobile router) is NOT supported.
I just read the TM-AC1900 was never actually supported, that's news to me after having merlin on mine for over a year lol oh well, I'll continue to mtd-write2 newer firmwares until it explodes