Does anyone have experience adjusting the direct trigger weight on a Zoli/Carl Gustaf single set trigger?

I have a Zoli 1900 in 9.3x62, the set trigger is great at about 1/2kg (1 pound), but the direct weight is well over 2kg (4+ pounds). Zoli's manual talks about adjusting the single direct trigger, but not the single set trigger's direct weight.

There is the direct trigger "adjusting" screw head under the bolt, above the trigger, but it is way to stiff for me to just twist and hope without knowing more. The trigger is a sealed assembly, unlike a Model 70's trigger, so I can't see to verify what the adjusting screw actually controls..

Any help would be appreciated. Getting it down to 1kg (2+ pounds) is what I am hoping for.

No experience with the set trigger cg's but the normal trigger is hard to get below 4# even after taking it apart. The little screw on the tang had little effect on the weight.
Heavier than you would like but very crisp and good overtravel. I like the serrated trigger shoe and shape too. The stock also fits me like none other.