judging the description, i assume you've used vgm_mm, right?
i've found a 'workaround' to the vgm export volume balancing issues, and its quite simple
just do different instruments for fm and psg, and then change the volume of the psg instruments till it sounds as you wish on the vgm. usually -30 on the volume operator on the instrument tab is enough.
thats what i did on my sgen entry!
also good song! sounds badass
it doesnt sound bad/unbalanced on winamp though (at least for me)