Hi Robert,
Your main focus was on the possibility of a hollowed trunk which would add interest to the tree. But what I struggle with is it's ramrod straight base up to the projected feature. the Nebari is nice but what I'm suggesting is that
after the tree is over the insult of the hollowing, that you pitch it forward
in the first picture angle about 25% more or less.
I think the line of the tree would more naturally suggest that this growth had started off on an angle and due to wind took the main trunk and damaged it as it became to be top heavy at that angle. Most things like this in nature don't occurr on a ramrod straight up and down trunk. It might mean
loosing some front nebari as you pitch the angle at replant the following year.
Since you enjoy this process, I know you know that the insides have to be engineered properly to allow rain not to pocket or allowed set but to be angled off and allowed to run thru the base of the hollow, so I just mention that so others who might want to begin studying the hobby would have something to be aware about besides just the outward appearances.
I quess my hunch comes from the various sensae's I studyied under that insisted that whatever we did to the tree that it looked beleiveable in nature,
Most classic trees have good movement in the base and growth refined at the tips and leaves full back to the main trunk along the length of the limbs.
So in the development of the tree, I hope you can do some cutting back on the tip growth to help refine the growth and hopefully push some dormant buds into coming forth along closer to the base of the limbs.
I see this tree planted in an oval pot that is yellow-green in color, with clumps of dark green moss scattered around the base. I think at repotting I'd be tempted to put a squarish rock in the back in what I would call a partial root over rock position as the reason why the trunk was angled forward. The rock would be a darker grey than the bark to contrast.
I have a korean boxwood that I put in the ground last year to repair from the loss of it's trunk that has come back quickly. I found the perfect pot for it and am waiting for the sale that somes at the start of the new year to make it more affordable. BUT as you suggest this is the time to be thinking about what needs to be done in improving our trees.
Bout time we saw some activity in the bonsai thread!
Dick Benbow
"The Koi Coach"
member Team Purdin