Just to give you a few more ideas. The is one my characters, SS Lorraine, for LF2. The scene is lit entirely with the Small Studio_05 from HDRIHaven rotated 180 degrees to put the light in the back in a custom background shader I whipped up for promos. I am using the Poser Physical surface node. The only thing done to the image is to overlay the partial SSS map and the arrow. The character render is a strait out of Poser using Optix, and Posers PostFX.

The scatter (scale) is set to 0.03. The depth of red, green, and blue, are all set to 5mm. No that is not a typo, 5mm

The difference? There is a depth map to control that 5mm depth, and lower it in a much more controlled manner than just using the red channel out of another image that has nothing to due with SSS at all.

This is one of the best ways I have found of doing SSS in just about every 3D program that supports it.  And it works just as well in Poser. This is basically the only way to control it properly; using a map that defines what is actually supposed to be going on under the skin, all over the character. You get full control over all 3 channels depths, up to the max depth you define (white would be 5mm in this case, full bore on all three channels). Other content uses the same approach, for a very good reason.

Keep in mind that I have Scatter Scale set to 0.03, (which is the same setting as Subsurface in the PrincipledBSDF node). And the depth at 5mm.......

You need a lot of nodes to do this with the Cycles root, and it is not very easy to do with the Principled one without node spaghetti either.

This skin shader has 5 nodes.  3 textures, a separate rbg, and the Physical root set to walk fixed. That's it...

The only better way I have found to do this, is with 2 layers of SSS, which requires one more map and a few more nodes.

Keep it simple, it actually works....

---

Some things are easy to explain, other things are not........ <- Store ->   <-Freebies->