well, chick1440 provided us the loader and profile for Z3 so there should be no worries for now. you can make a backup of it and you can flash it with RSD Lite 3.1 and 3.2. can't be recognized by 3.0 i guess.
i don't have a Z3 but i'm studying on it. waiting for this model to come out. afaik, Z3 can only be detected by RSD Lite 3.1 and 3.2 and FB3. other p2k programs still can't detect. might be a new p2k driver needed for this model. i studied the flex, seems like you can edit only the splashscreen*** blah blah gifs in the phone using a java app that can read phone directories. it's SU and SD is different compared to other models. it is nto custwakeup.gif or custgoodbye.gif.