[dkga]

Any recommendations / lessons learned when building this? I would love to give it a go for Brazil if one doesn't already exist around the time of my holidays in June/July.

[sam_lowry_]

Just take the source, and ask your LLM to do the Brazilian version. It should not take more than a couple hours, including manual checks.

Do not forget to minimize the geojson (there is even a web-based service for that) and to enable compression in your web server.