No, once the trees get established, you treat the thing as if it were one tree. The roots get all intermingled. Repotting becomes a task where you remove the forest from the pot, scrape off the layer of matted roots on the bottom, cut back any really heavy roots, trim around the perimeter, add new soil to the pot, and pop it back in. Easy Peasy.
For the canopy, I am only treating the main tree a little differently than the others. I want the main tree to be thicker than the others. These were created from seedlings, all were about the same caliper. So, to have the main tree to be bigger, I’m letting sacrifice branches grow out the apex. Each year, I’ll remove the sacrifices, and start new ones. I’ll do that 2 or 3 more years until there’s a noticeable size difference, and then it won’t be necessary any more.