Flash T mobile stock firmware onto SM-N910A?

I'm using an at&t note 4 on tmobile and was wondering if it is possible to flash tmobile stock firmware in order to use features like wifi calling? I figured since the hardware is the same that it might be possible. I'm sure someone has instruction somewhere on how to do this but I have been unable to find it. Any help would be appreciated. Thanks.

ATT Samsung Galaxy Note 4 SM-N910A Repair help

I have a bootloader locked ATT Samsung Galaxy Note 4, Model SM-N910A. While trying to downgrade from Lollipop to KitKat 4.4.4, i ended up wiping the phone clean & now ODIN does not work. Got sick of trying to resurrect the phone. Since i can't root this piece-of-****, i just wanted KitKat 4.4.4 on it. Can anybody recommend me a repair shop that can restore this phone. I live in Sterling Heights, MI. After sinking 2 on this phone, I'am not willing to spend anything more than on this, though.

Thanks & Regards

Cecilia