Nodial, I have been trying to enable GSM and additional LTE bands in my SM-T807P without success.
As far as I could see with CDMA tools app, the LTE bands that my device uses are not what I need.
However, I saw that in SAMMobile I can download the SM-T807T ROM 5.0.1 (T-Mobile) that uses GSM / HSDPA / LTE bands that matches my local carriers.
I'm going to try to flash the SM-T807P and then, unlock & debranding.
If you think this is crazy (because there is no way it works) or the trick surely only will brick the device, please let me know to avoid the test...