One thing after another. I see there was a thread elsewhere about someone trying to make rib definition, visible ribs, for the G3 Female. I found two products that maybe do it, but their product images don't show any pronounced ribs.

Is there any such thing for G3M? Anyone have an idea of how to do it?

To create pronounced ribs for Genesis 3 Figures you would be looking at either applying Normal maps or using Geometry Morphs.

There are numerous existing Body morph sets for the Genesis Figure range which can be used across the entire figure range using utilities such as Generation X 2 from Dimension Theory at Daz 3D.

Its hard to say which ones would suite your specific requirements based on your description here. But maybe a Character preset for Genesis 3 Male such as Giani 7, or even Lee 7(HD) if your looking for something slimmer, would be the simplest solution. Character presets can be used either as a complete morph including the head or just as a body morph.

Slim doesn't matter. What matters is if the ribs are pronounced. Lee 7 is a possibility from the promo images.

Lee 7 gets it part of the way there, but it's a full body morph. It looks a little involved to isolate such a morph to one body part.

Even if that were possible, L7 doesn't get it to where I want it to be with the ribs. Look like for Lee 7 it's more muscle definition than ribs,

It's frustrating there's no way to make a body morph for G3, because even with my limited skills I could do it for this.

I'm not sure what you mean?

There is no reason you cannot create your own morphs, you cannot create HD morphs based on SubD Geometry, but making a normal morph is pretty straight forward.

This would be a good place to start:

http://docs.daz3d.com/doku.php/public/software/dazstudio/4/userguide/creating_content/modeling/tutorials/pbms/start

What's the difference between a HD morph and a morph?

I tried deformers - it's like trying to do something by commanding drunken, blind fleas. Off to Blender.