potting up a plum tree on a mustang rootstock

potting up a plum tree on a mustang rootstock. it just worked out for our growing space and late spring grafting that this year all the grafted plums are in pots. what's interesting is the fibrous root system of a cherry plum hybrid stock seems to grow well in a small pot, you can see the healthy white root hairs, no circling roots, not too densely filled, in my experience just the right time to pot up. if I tried this this apple the thicker roots would be all tangled. I'm new enough to nursery work that several methods are getting experimented with for just about everything, but one thing I've consistently found is methods that work for large growers aren't the only way that works, and small craft scale growers may benefit from these slightly more intensive and time consuming methods, you almost just have to try it and judge the results to know.