Try pluging in the color channel of the base color into the subsurface color of the material.
You should then be able to increase or decrease the output with out having to use the emissive workaround.
As an after though you could try using an HDR map to control shadow density but personally never been a fan of GI solutions.
Added
Looking at the material BP your missing roughness and spec.
Making a PBR material is like making a chocolate cake. Miss one key ingredient and it’s not going to work.