I could take a picture of a couple of cuttings I have which resemble the fattest cuttings towards the middle-left in that picture. They are dark, olive-drab colored wood just the same as pictured, and have the little mocha freckles everywhere, but ... little buggers never rooted. Some are budding as the two big ones pictured there, with all those little freckles everywhere, but for weeks...not a single root. With all that energy wasted putting out those initials/freckles, you'd think they would have sent at least one root out, eh?
The other distinct feature I noticed were groups of freckles that clumped together and left a brown and white scar which never formed roots. I don't think I ever thought about or noticed any of these things before because I didn't root in a way that would allow me to see the patterns. This year has been very interesting!
I'm going cutting-fetching around my neighborhood this weekend on some of the larger trees to root up some unknowns, if for no other reason than practice before UCD cuttings get here, and to get some cuttings out to a couple of fig friends. I will be interested to see them through their growth, and watch for this stuff.