We have now produced 812S firmware that supports bit setting for +R media :).
Edit: Bitsetting now works with +R and +RW media.
Below you will find code65536’s tool to patch your favourite firmware. Here is a link to my page where you will find already patched firmware BIN files (UYS1, US05, US0F, US0G).
code65536 and I don’t have an 812S so this is especially for all you 812S users out there. Enjoy.