If you have to send a flasher back to have it reprogrammed you'll have to flash the stock program back on before you do to "unlock" it. At least with the SCT flasher anyway. I'm not sure on the Predator though.I would prefer a flasher over a chip anyday.
I would rather have the tune in the computer and then when are ready to add some new mods, you don't have to roll 'tuneless' while your chip is reprogrammed.
My car passed PA emissions testing with an SCT chip no problem. Twice.Flasher are IMO better because come emissions time, they can be manipulated to change your system to pass and keep whatever mods you have on...for the most part.
Also, the chip is like a piggyback, where you cant go through emmisions with that attached to the PCM...it will confuse the [censored] out of the diagnostic machine. A flasher reprograms the PCM settings..undetectable(at least so far).