Personally, I would prefer trees on other things than FD. I’ve found a semi-dwarf such as C-35 or Standard Trifoliate, or even US-942 are much better choices, even in containers. FD in containers tends to grow about 1.5ft and non stop fruit, rarely putting on any other foliage. So leaving the tree rather bare and to struggle a lot. Just my personal preference though. Trees on FD rootstock just grow so awfully slow!