Well, against my better judgement, I started playing around with a 4.1.2 port. As I suspected it was a gargantuan pain. I hadn't planned on releasing it until it was up to my standards, but, it's pretty good right now and I'm just so tired of screwing with it. So, it is what it is. If you really want it, this is what I have so far. Don't expect much support on this one, and expect none on this version when the I747 ROMs are finally released.
It's extremely stable, except I cannot seem to remove all traces of tmo's Wi-Fi calling.
Their Wi-Fi calling is also SIP based, and tmo chooses to implement it by taking the place of the Android native SIP/VOIP calling. Therefore, there are some issues with the native app and how it works. I was able to remove most, but not all, traces of tmo's stuff. So you can use your own VOIP account, but only if you check the Settings option to stay registered and also receive calls.
Also, another reason I wasn't ready to release this, the tmo WiFi Calling toggle is still on the Settings menu. Just set it to off the 1st time you boot and leave it alone. Finally, there are 2 Wi-Fi calling related apps running still in the background. If you remove or freeze them, you will lose your network signal completely, meaning Ghostbusters symbol instead of signal bars. If you don't mind the 2 apps eating a little memory, there aren't any bugs I have found.
Lastly, welcome back Call Recording!
Blue only for now.
I747t T-Mobile 4.1.2 Port As usual, re-Odexed (for her pleasure)
Multiview all apps/wifi-BT Tethering/24-toggle-Precise battery mod, etc. Only difference is fewer languages.