I seem to be having trouble with elements that only have a category and no subcategory. I can isolate The elements I need by type, but ist a tedious process because we literally have hundreds of types. Is it possible to develop a set-difference filter in addition to union and intersection? Or is there a workaround that I’m not thinking of?
If I understand correctly, you are looking for a component called ~“Exclude Filter” (their is one for types and one for elements) which excludes input elements from the queried elements, if not what you are looking for please try to elaborate more or provide some sample/example.
I’ve tested “Exclude Filter” on the “RAC_basic_sample_project” and it does what I’m after. Not sure why but it seems to take forever to filter a larger set of elements. I’m not sure how the filter works under the hood I suspect it processes everything in the model excluding the input elements?
Having a second look at this I seem to have forgotten to connect the main set to the “set intersection” filter 
Ok… Sorry for the confusion. I’ll had to delete my previous post.
I think this screenshot is demonstrating my problem better.
It seems like the Type filter (445 elements) are being excluded while the subcategory (2289 elements) are being ignored
I think you can use an “AND Filter” connecting both the category filter and the exclusion filter as inputs, then the output from the “AND filter” to the query elements.
Also, instead of having the 10000 limit, you can zoom in on the query elements component and remove the L input using the “-” sign that shows when u zoom to components.
