Hey I understood what you meant. The result that you are trying to achieve is very close to the browser caching normally present is what I meant. When you zoom in it will only load that area. And I don’t think you can specify the number of tiles to be a specific number, since the zoom levels are not linear.

The offline leaflet I shared in the previous comment actually does the same thing you want to achieve. The difference is the offline mode is discarded immediately when the system is back online. So that library must be adaptable to incorporate the time dependency and users visiting a point again I specified in the last comment.

Regarding OSM data, there are zip files available for downloading. Geofabrik and openstreetmap.fr are examples. Another tool is Protomaps, where you can download by drawing a polygon. But these are not going to be the ideal solution for a product like Immich.

By the way I saw your update. Great job on following up and providing a fix for others. I really really appreciate it.