I'm making some progress, but 3600 seems hard to stabilize with 2400 divider (145+ refclk) or I still haven't found the right knob.
VDDSOC doesn't seem to help much after certain point. Some other voltages help a little, but not much. Still left to bring down the temperature.

Got it 1sec faster on next 1777MHz mem freq, now trying same at 11-11-11, however 3600 is a no go for now with this divider.