And one final update, from Sheri at KSU:
Hi Dana,
Yes, pawpaws can be pruned to keep them smaller height and width-wise. You don’t want to prune too many of the tips of branches off though, since pawpaws produce fruit on one year old wood. You can see the flower buds formed for next year already (round buds in the leaf axils), so just be sure to leave enough to produce a good crop. Pruning should be done in late winter or early spring, after the coldest temperatures are over but before they break bud. Pawpaws can be pruned to a central leader like an apple, or they can be left mostly unpruned, it depends on the space you have and your preferences for how they look, there are pros and cons to each but not dramatically different (central leader pruned trees take a little longer to come into production and produce a little less the first couple of years since you are removing some of the fruiting wood, but they are much easier to harvest from and mow/weedeat under). We did not see sunburn on any of the fruit of central leader pruned trees. Southwest injury or sunscald can be a problem on exposed pawpaw trunks in full sun, so that would probably be less in trees with lots of lower limbs to shade them, but trunks can also be whitewashed with diluted latex paint to prevent southwest injury. We have not observed a shorter lifespan of trees that are pruned vs unpruned.
If you have any other questions, just let me know!