Let me add my thoughts into this.
I have had both species of trees albeit the Blouhaak gave itself up to the bonsai gods. I blame myself for that because of my inferior knowledge with the species.
Looking at the Blouhaak of abNormalza, there are loads of buds all over the trunk so it definitiley shows that it is a healthy tree. I would not do any work on it now as the cold is starting to set in here in SA and any serious work could kill the tree. When the weather starts to warm up and one can see the buds starting to form, I would repot it into a much larger pot with much better soil, do a trunk chop and regrow it into an umbrella shape should that be the way to he wants to grow it. It is one of the hardest lessons that I still sometimes struggle with is to cut back on a bonsai to start the process again. But slowly but surely I am realising that in the long run it will make the difference in having a good bonsai.
With regards to the black monkey thorn I would do the following. Again no work now till the buds start to break. Then I would also repot it and sink that tangle of roots under the soil, thereby leaving a smaller gap between the top of the soil and the lowest branches. I would shorten the tap root too but leave enough of the root system for the tree to survive (Vague I know but I would be working with the tree to see how much to leave etc) I would personally start to wire the lower branches into a upwards position so that as they grow they become part of the canopy.
I would be using this image as my guide line.
Or maybe even this one.
I have done a very quick virtual of what I would do with the tree, with the brown being the soil level
I would then also do a severe cut back on the long branches as per the following method that I picked up by a guy called Lennard. Cut just above new buds that are breaking (Purple line) so as to leave some part for die back.
The bud will grow out thus increasing your ramification and overall structure of the tree.
But that is the way I would do it. It doesn't mean it is right but that process has worked for me and that is how I see the tree.
Thoughts?