All other software , including wattman seams to work best when the P1 to P6 are disable for GPU and P1 / P2 for Memory, using 1 profile at min/max .  Allowing GPU to run only 1 state like that it has no oscillation, would that be a solution ? Of course in idle you have a high power consummation, but no miner should stay in idle with the GPU's, or default settings of GPU could be reset before quit script.
Thanks,