Ah the mysteries of the BIOS updates. It does seem strange that they would add the control option only to remove it again in the next update but sometimes these things slip through the net and it is only when users raise a query that it is noticed.
It is one of the many reasons that Flashing BIOS shouldn't be undertaken lightly for, although an update might fix a known issue, it can often result in other features being lost.
Hopefully you will be OK with the F6 BIOS but, if you still have problems let us know.