This seems potentially related to
DAFFODIL-2162. That issue was resolved, but it now results in a warning about dfdl:choiceBranchKey property is unused. The tests clearly show that direct dispatch works so the branch key isn't actually usnused. Perhaps the property is being cached on something that we aren't looking at to see which properties have been used, or the property is being used in a way that isn't caching at all.