Interesting and thank you both.
Looking at the instructions again, they suggest a curved, rather than an angled bend to the dropper might work better.
Further experimenting certainly required though, including:
Building a test rig so stock can be pushed back and forth on the work bench
Try altering the height of the magnet. I use the Dingham ones and on 15v, instead of 12v, as this works better with AJs, so maybe there is an issue there.
Vary the length of the dropper as the shorter it is, the greater chance for the loop to fall back down on its own weight
Find some way of ensuring the loops don't go beyond the vertical, as once they do, then there is no way they can fall back again.
As for loops just at one end, am doing that with some of my trains as it works well with fixed rakes. However, as soon as haunting is involved, it all goes to pot because having a turntable means you soon get a loopless loco with a loopless wagon.
Overall, I'd happily use three links and the hand from the sky, but for front operated exhibition layouts that is not practical for the paying public.