February 28 2021 - Seems to strike easily. One cutting has visible roots appearing in the bottom of the bag after 17 days.
Update: March 2 - All three cuttings are showing roots now.
Update: March 19 - Potted these up once root development looked good enough. One is now going to kark it. It was fine for a week or so, with good foliage production from one node. It then started to die from the top downwards (ie: wood above the level of nutrient production died, then continued that down the entire stem). At the moment there is still a very narrow strip of living tissue, but the leaves are starting to die.
This was not due to a failure of roots. The cutting was well rooted, but the upper 20 mm had gone brown some time back. This appeared to be stable, with the rest of the stem a healthy green, but suddenly progressed all the way down the entire stem and into the mix.
It is likely the other two cuttings will also die. Again this is not because of lack of good roots. One has them even poking out the bottom of the pot. The problem with the other two is there don't appear to be any functioning nodes above ground level. There are nodes, but they appear to be kaput, so to produce new foliage these two cuttings will need to create new nodes from scratch. They may not have enough oomph to do this.