Hi Mike, this is great!
Your outline structure suggests a flow chart for picking data structures. Is this the intent? It seems like a good idea, as it would help people pick the right structure before worrying about speed.
As to the libraries: this might require some coordination with the authors. For example, my elm-avl-exploration repo was obsoleted by Ilias', despite providing exactly the same API. Like the repo suggests, curation here is required.
Lastly, I'd love to help you create good benchmarks for this. We can modify elm-benchmark to support this if need be. I *think* it should expose everything you need to make a custom runner already, but I could be wrong. Feel free to email me privately about this with any questions. (or #elm-benchmark in Slack)