Doesn't look like you have enough foliage at the top to even support the air layer. I am a guy who like to strike cuttings, take air layers and grow a bunch of seeds... aka hoarder.... but in this case, I don't see it.
Looks like a pretty cool tree. Problem is you live in a zone that is not friendly for JM. I would be a bit more cautious on working too much on the root. I would keep it in full shade once the temp creeping up above 90.
Uncle, that could be a variegated variety. LOL. Looks like my water jasmine leave... but I know what is wrong with mine.... they are hungry for food and need a repot.