I think with Optiarc BD burners based on a NEC/Renesas SCOMBO chipset design, you're probably out of luck here. No idea about other manufacturers. Most LiteOn drives support bitsetting on DVD+R but I don't know if they have slimline BD burners.
If you manage to figure out their firmware encryption, it might however be possible to modify Optiarc firmwares. But at least I have been out of luck so far