Hello.
You said: "2. Only the source step will be available in the reference table." This is NOT true!
I have tested it myself. I used a spreadsheet as data source, which produces a list of tables, sheets and DefinedNames. I filtered the Kind column to just the tables, then referenced it in another query. The referencing query also contained just tables - there were no other objects, as there would have been if your point 2 was correct. Please update your post.