To test the new ability to plant trees by hand without treeplanter's pots, I planted 44 bushes. Here were the results.
13 reached full maturity (30%)
31 were stunted (70%)
This seems higher than I would expect. I did not test trees, so I don't know if there is a difference between bushes and trees. It is also possible that I just got horrific RNG. But I would be curious to hear if others have had this experience. I think that an average stunt rate above 50% is too high.