Question: How Transparency affects Cast Shadows, and Subsurface Scattering

Acute

Been encountering interesting issues where transparency and subsurface scattering coincide. I'm wondering if Marmoset 4 just doesn't support the combining of these features currently or if my setup is wrong.

I have a cutout mask used to subtly alter the outline of some fin membranes. However enabling it also seems to disable my subsurface scattering.

Transparency also seems to remove cast shadows from the mesh it's applied to.

Is this normal behavior or is something messed up here in my scene?

Thank you