Got it working! at least at the moment
2 versions of the graph below; they use slightly different methods to get everything and process it. One version uses the methods in this thread, albeit sloppily; V2 reuses some code from the delete subcategories graph I put together earlier (found here.)
The updated version to set subcategories does rely on the Element.SetSubCategory node from Clockwork that is currently only in the Git repository. Thread discussing it here: Reassigning subcategories
Next step will be to figure out which one will work best long-term and clean them up.
Thanks for all the help! 
is on me. 
Family-SetObjectSubcategory.dyn (27.5 KB)
Family-SetObjectSubcategoryV2.dyn (25.7 KB)