Hi, yes is good méthode, working for the voltage to ! If you have set 300mhz, replace 0706 by 790mv, on all m'y test 790mw IS lower value stable... Make 790mv and you see you low power and lower temp !

If you interessed, i have make specialy patch for S9 and T9+, juste make --fix-freq and New miner configuration page , full free

PS : Kano, i have Big respect for you, but now you see again, don't need modify bmminer or cgminer for make this tweak