I would imagine that with IDPS you could put anything on your console with a backup. If you make a backup of your console with paid DLC in it, and restore it on the same console, the paid DLC is still there, so the .edat is definitely getting put into the backup, just in the protected archive. IDPS gives you the keys to putting anything you want in the protected archive.
I'm sure another IDPS grabbing exploit will eventually crop up. As it stands right now, IDPS is stored on everyones hard drive already (supposedly in the PSN Store storage), so all it will take is an exploit to get any file off the HDD. I have a few theories on how maybe to do this but I haven't experimented with anything yet.
Is this a thing? I'm not that educated in the PS3 side of things.