According to the documentation with the firmware from Liggy & Dee's site, the RPC1 firmware should include the Riplock patch.
NEC ND-3500A 2.1B Firmware
README.TXT - This file
21b_rpc1.bin - 2.1B Firmware including Riplock and RPC1 patch
Rip Lock removes the rip (reading) speed limitation,
(usually set to 2X) on a DVD Video with CSS encryption.
RPC1 removes region checks and commands.
There is a risk involved in flashing with experimental firmware,
so if you do not wish to assume this risk, please do not flash your drive!
This file was downloaded from http://liggydee.cdfreaks.com
This is not so as the image below indicates. It is clearly RPCI only and not Riplock Removed.