How I treat cuttings that are harder to root.
This is what I do to some of the problem Angels. I take a 2.5" pot, put some cutting mix in the bottom, then place a 1.5" pot in the middle and fill in around the sides with the mixture, firming as I go. Any compost that gets in the middle pot is emptied out. Place the cuttings in between the 2 pots, firming in around each one. As you can see in the photo this works well as all are rooted. I removed a cutting so the inner pot could be seen.