[FR] Client side geometry generation for known indexes (H3, S2, etc.)

[AbelVM]

It's quite common nowadays to have raster-like data (continuous coverage) stored as key-value tuplas using H3 or S2, without geometry, so the stored data size is minimized.

It would be great to add client-side geometry generation to those spatial indexes so the tile's payload is stripped to its bones, in those cases it's possible. Something like Unfolded' hex tiles

For the last 2 years, I've been using a custom protocol in production to achieve this, but I'm sure that this feature would be welcome as native in this upcoming format