does that mean
does that mean without the IMS-based client, you can't make phone calls over LTE on T-Mobile? Currently the wifi-calling client isn't a downloadable app because it requires a custom ROM and is only available on stock T-Mobile ROMS. Assuming that will continue to be the case, does this mean if I buy a future LTE 'nexus' phone or flash a different ROM on my LTE T-Mobile phone that I'm SOL if I wanna make calls over LTE?
oops I meant 'custom kernel' not ROM
I don't think so. I know that it does not matter the version of android, from what I understand, the phone must have built-in IMS capability. So far the only phones that T-mobile offers with that new IMS wifi calling is the Amaze, Galaxy S II, and LG...