Actually I had a similar question. Does anyone know/tried to flash the Verizon one with the T-mobile one firmware. Generic firmaware is better, but i dont get network in my office, so with the tmobile firmware I could use wifi calling.
If flash firmware is work, maybe can install android version too.
Need wait crack, now wp8.1 couldn't do anything for that.
I want to adjust NV date for M8, but M8 couldn't link to QPST, more limitation.