I do suspect that growth habit is due to being in full sun, I think they are naturally an understory tree and likely bush out more in part sun or dappled light. But it’s just a suspicion. Have you gotten fruit yet?
The leggyness would probably have more to do with how ever the nursery kept it, I’ve only had it for a few months. It is pushing branchs at the top, so its possible the nursery trimmed most of the lower branches off to ship/store better. I looked up some pictures on google, alot bushier in the pictures, but I can see how it can grow from how it looks now to that. So I retract my bad shade tree statement, it’d be pretty good.
Hasn’t fruited yet, but its been cooler at nights then I’d want to be, plus transplant shock into our native sandy soil.
I can take a picture of it when the sun comes up.
I grew mine from seed, hard to say what it’s done has been growing. Basically it was fighting off death ever since sprouting but now it seems to be moving a little bit. The type of foliage seems very tender so I imagine wind will batter it, similar to Starfruit. I have to keep mine is a super sheltered spot to avoid being wind whipped
Here are the pictures of the peanut butter fruit trees. The bigger one went into the ground a month before the smaller one. The bigger one has probably put on over 6 inches of growth in 2 months, the smaller one probably just under 6. Both have been in full sun after some precautionary hardening off.
Bigger tree.
Smaller tree.
That foliage looks nice and hardy, maybe once mine sizes up some it won’t seem as fragile as I thought after all.