this is how to install duplex releases on this CFW.
1.install as normal
2. open Multiman or other FTP server app and PC side client then log into your PS3.
3. locate the game folder on your HDD. (HDD/game/Insert GameID here/USRDIR/)
4. download the eboot files and any Self/SPRX files.
5. run the eboot through the 4.21 resigner.
6. If there were any self/sprx files they will need resigning as well. this must be done manually please read the instructions for the tool you use.
7. Copy the resigned files back to the PS3 with your FTP client.