AusBonsai

Looks like a handful of fun projects, Neil.
I especially like the ROR Tridents you've got going, a few years of branch refinement and they will become show stoppers. Wish I could get my hands on stock like this, a real credit to your growing/development skills

Some imaginative trunks there, particularly in the ROR lot. How will you get the low half of no.2 to thicken, while you hold back the top? Can you get low back-budding for sacrifice branches?

A very good question Gavin and I cannot give you a definitive answer - yet. Note a recent reply from assistant curator NBPCA that

You can still achieve gradual taper when growing trunklines or apex fast. The careful use of sacrifice branching in the area that you need more girth will help you out.

but not sure that is the answer here. Excess (sacrifice) barnching has, in this case, contributed to the problem instead of solving it.

I intend to try wounding on the lower trunk while holding back development of upper areas - defoliation, severe pruning, etc and Will keep you all informed how it goes.

I think you could thread graft a branch low down to run as a sacrifice for a few seasons. You could also graft on more roots to give the illusion of a more spreading base?

Still working through the tridents. This one is still in development. I picked it because it has such an extreme trunk for a trident. I'll need to watch out i don't grow another of those too long tops on this one.
I cut off a major 2nd trunk last winter so have allowed the new shoots to grow to start the cut healing. I think it had 1 summer prune this season but i will have to try to remember to pinch it more regularly next season to start ramification of the branches.