Was it very root bound? I ask because sometimes those bushy large JMs in containers come out with roots in a giant cylinder. I planted one like that last year, and now I need to dig it up, work on loosening the root ball, and put it back.

I'm fairly new to JMs (in the past three years), but I think it would probably be good to trim yours back gradually. You don't want to take off too much, but you also don't want to watch an unwanted branch get bigger and bigger or the resulting wound from removing it will get bigger and bigger as well.

Many of my JMs are young, and with most of them I left them for a year before doing any pruning, but when I buy a new one and I know I won't want a branch, I usually keep that branch in mind and trim it out during the next good pruning season. I've read that winter (Nov-Feb) is the best for pruning branches larger than your pinky, and a dry summer stretch (June or July) is good for pruning smaller branches. I know some people say to let the tree grow for 2-5 years before pruning, but usually when I prune I have a very specific structure in mind. If a branch is in an ugly spot, it's in an ugly spot. Three years won't change that.

I'd spend a long time looking at its current shape once it's in the ground, giving yourself a season to get to know it in your landscape. Don't trim anything yet-- you may decide after a month or two that you'd like to rotate it or see the branches from a different angle. Once you're satisfied and know it well, then sit down and come up with what shape you think it can attain with its current branches. From there, mentally remove one or two here or there and see if it's an improvement. Waiting until next winter may be a good choice-- you'll see the form more easily then. Sometimes I sketch the main branches out on paper so I can more easily envision the shape of the tree once these little branches are more like trunks, and the tree has grown significantly.

It's a beautiful tree!