This plant from several months ago, the leaf cluster stem coming towards the camera at the bottom:
Didn't notice then the branch was snapped right off the stem.
Neat part is that as it slowly droops, this plants is already sending tiny coarse roots down (from all the branches, but in this case I see why).
The roots on this barely broken branch just hit the pumice yesterday morning and have already latched.
Figure I can either:
leave it, let it root and cut it from the mother but hurt the roots if I transplant it which I probably would
cut the branch at the stem now and root it
excavate the 1/4" that taken hold, carve out enough substrate for a shallow dish of soil and pumice, some sharp sand if I still have some, and let it root into that, then sever it.
I'm thinking excavation.
Pictures coming but it's dark by the time I get a chance to take photos, sorry.