Both are good points! In my effort to keep this "simple" I left out a few use-cases, which you both have covered. I'll modify the article shortly to take them into account (once I've tested and verified there's nothing else missing here).

There's definitely no harm in completeness!

EDIT: New version published. While I can't include every single possible use-case for index properties, these additions provide good examples of how to customize these scripts & ideas to specific situations.