Steps I took.
Enabled bulk edit on a screen, and set the tag loadDynamicAttributes=“true”.
Go to my screen, select multiple entities and hit the button Bulk Edit.
Result:
Bulk Edit screen comes up, but it contains all possible dynamic attributes for that entity, not just the dynamic attributes for that category. In my case the entity has 4 possible categories, and the screen contains all dyn. attributes from 4 categories, even though the selected entities where all from 1 category.