I think this does what you want http://forums.sketchucation.com/viewtopic.php?p=346362#p346362 'TIG.colorthinfaces'...........
If you want it to skip small curved surface facets it'll take more coding...
These can be ignored and re-colored anyway. The problem is that a small facet might be ignorable but the total assembly of then might still not be thick enough ? For example a think cylinder would pass if the smoothed faces were below the limit, BUT it ought to fail as its cross section is too small anyway ??
Trying to consider all connected faces is not workable either because a solid has all of its faces connected anyway 😒
I suppose if we find such a face below the size limit but smoothed we can look at all of the faces that share its edges ? Then if the angles between the face and any of its neighbors is less than say 30 degrees [internal-convex] it fails. Otherwise it's assumed to be on a 'surface' like a cylinder/sphere/mesh... Now to think of how to code that... 😕