Only 5 bytes differ between original PX-716A firmware and patched RPC1 firmware (2 bytes are checksum). So patched firmware will not be harmful. But if you don't need multi-region playback environment, I do NOT recommend to install patched firmware.
Because region free firmware under Windows environment is troublesome. Recent playback software such as WinDVD or PowerDVD also have internal region setting. These softwares always deny to playback commercial DVD with region free drive. To overcome this limitation, Slysoft AnyDVD is required.
With Linux OS, drive with region free firmware is very comfortable. Typical DVD playback software for Linux, "Xine + libdvdcss" does not have internal region setting. You can playback commercial DVD from all around the world without any limitation.