This is the from the rock's prespective. I remove the entire section of last year's root growth, about half an inch layer from the bottom.
The pruning of the limbs is primarily nipping every branch back to only two healthy buds. Some major branches up to the diameter of a pencil were removed to stunt growth or to open to growth below.
Not a whole lots of difference but that took about an hour.
Another perspective, before above, after below.
Replanted onto fresh potting mix layer about 3/4" thick.
A grouping of five trident maples on rock slab.