Thanks for the thorough explanation. Now what is the easiest way to flash those us files on the dual sim? I need to get mine ready. Does it factory reset the phone in anyway? Where can I find instructions to flash. Is there any way to do the flashing without a computer?
So flashing will only give us volte on verizon? Also need volte on tmobile working. Are any devs modding the modem files so that we can bypass any block or having no approval from tmobile/sony to certify volte for compact?
I think I downloaded the USA firmware using XperiFirm and then used NewFlasher to *only* flash the OEM.sin and OEM_Extra.sin files...this didn't affect the phone in any way I could tell except that it enabled Verizon VoLTE. It did not enable T-Mobile VoLTE however...but this was a month or two ago so maybe Sony has gotten T-Mo VoLTE working? Not sure. Good luck!