Originally Posted by hddr3
I want to install CM11 on my t-mo xperia z but don't want to void JUMP , if I unroot, reinstall factory image and re-lock bootloader by time I need to turn phone in will it not void JUMP? I come from a Galaxy Nexus and miss having stock android
I just bought a Xperia Z from T-Mobile myself today (Blackberry Trade in Promo, $6 down!) and was just literally talking about this very concern.
I'm going to bypass the Bootloader Unlock and attempt a root/recovery without unlocking it. At that point there shouldn't be an issue with flashing a custom rom. As long as you can flash back to stock (stock recovery, stock firmware) you should be fine. There seems to be a handy "flashtool" in one of the stickies that will explain how to do this.
I imagine you at that point should be fine. I would advise: do not unlock your bootloader. Most OEMs (I worked for HTC for many years) watermark your device and it's a pain trying to remove it.
Worst case scenario you can always do a warranty exchange to get a fresh device before JUMP upgrading later.