I know you can get back from verizon, i haven't tried at&t so i can't say for sure. I personally think you could probably switch between all the latest carrier firmware but i have neither to time or patience to test that one.. when i flashed t-mo firmware i tried lots of stuff to get back and one of the things i did bricked my phone completely, no usb recognition no screen no button action, just black screen would not turn on. i think since you already moved to BL rev 4 i don't think you can roll back to flash this. what you are required to flash to get this to work is a different bl rev, so you'll get an aboot error in odin. as i recall my brick came from flashfire, not odin.
and yeah, that was me with the 1st version of the rom that only worked when you flashed t-mo. and i'm not flat, i'm edge...fyi. This was/is a great rom, i hope it makes it's way to nougat for us but i doubt that will happen
I see I wasn't sure if I could roll back anymore or not,
If we ever get the U firmware on nougat, that would be enough for me. Thanks again for the info.