The ease of creating and using separate “index” palaces (vs packing the same information into your “main” palace") is so much greater—for me at least—that I regularly create new indexes for nested information structures. Saves me a lot of time.
No new "tricks"are even needed for remembering the indexes. I literally just review the indexes when I reach the point of my “main” palace where the index is referenced.
On Memorizing Procedural Logic Structures:
I literally just wrote a comment to @erikfromholland sharing a couple thoughts on this. imo, the exact same concepts are applicable to your terrible MS Paint diagram. 
—> Pseudo-code Palaces comment
Three cheers for mnemonic documentation as procrastination!
