[Myst3ry]

Quick Question...
Alright guys, so about two days ago i got my new TP2 for Sprint and i already knew about custom ROMs and where to find them as well as the HSPL (here) so since i got it, i have been doing nothing but research ROMs since yesterday... i have no worry about flashing my device, but there was one thing i was not able to find while researching...

-If i flash a custom ROM on my TP2 for Sprint, and then later this month (hopefully) Sprint finally decides to release the 6.5 update, is there a way for me to use the official Sprint update once the device is on a different ROM? will i have to flash back to stock ROM? will that be enough, or do i have to re-lock the device?

(as much as i may like custom ROMs, that doesn't mean i am not going to want to try the official releases)