I was thinking about this some time ago, but even if we add POIs to the DVD, the RNS-E does not have any "poi warner" so we would need to drive looking to the navi to see if there is a camera in your way, I think this is not very useful.
Too much work for just see a icon in the screen.
There is a easier way to do that, we know that we can send TMC events to the RNS-E, probably we can modify a MP3-to-FM adapter and send POIs info to the RNS-E locally (in TMC format), and in this case, if there is any camera in our route, the RNS-E will warn about it.
It's just an idea, probably easier than modify the firmware or spend a lot of $$$ trying with the DVDs.