Feature request: Selective re-generation by area

I'm having trouble finding a workflow to use when a part of a large dataset changes, with changes confined to one specific area. For instance, I add a couple of data sources to opentrees.org in the Netherlands. Currently, my only option is to re-generate the entire tileset (~40 minutes and growing).

I tried generating tilesets for different regions then merging them together with tile-join but that doesn't really work if the regions are close together - per-tile limits quickly get exceeded, which tile-join resolves by keeping neither tile.

Would it be possible to perhaps have an option to selectively update an existing tileset, within an area specified in either lat/long or tile coordinates?

Start by reviewing the existing full tileset generation workflow and the tile-join behavior described in the issue. Compare how selective updates could use an area specified by latitude/longitude or tile coordinates. Done means an existing tileset can be updated for one area without regenerating unrelated regions or exceeding per-tile limits.

Written by the indexing model from the issue text.