but with vdd mod disable and vdd set to 1.5v (the best settings for my mobo) i have a gret vdimm drop, like 0.12v from idle to load....
mmm... could be an "reading-drift" in your hw-mon software.
both have nothing to do with... normally..
try an multimeter... ?

yes, disabling the vdimm-supply and adding extra capacitance makes the mod near perfect.
an possible way could be simply lifting the right leg of mosfet(s)...