For it to work, you will need to fake-sign the EBOOT.bin and replace the original. Then you can boot the game but you still need an original game in the drive for the backup manager to work.
I hope someone would step up and code a HDD manager for the debug owners (this will work for retail units with psjailbreak too). I see an immediate need for such a handy program considering managing PS3 HDD files is such a pain in the butt. HDD manager with FTP support would be the best.
Maybe we can figure out a way to patch all currently released ps3 scenes releases to work with psjailbreak. For games with single file > 4GB, use FTP to transfer to internal hdd to play. For games with files < 4GB, just copy it over to USB HDD. Just my two cents