Make use of btrfs snapshot serialisation?

[Atemu]

I noticed that you go through quite a bit of trouble creating small btrfs images in order to "package" a btrfs into something you can send to the web server(s) to serve.

In case you weren't aware, btrfs has a filesystem serialisation feature built-in (btrfs send). This takes a read-only snapshot of a subvolume in a local btrfs as input and produces a stream that can be de-serialised into a snapshot inside a separate btrfs using btrfs receive.

Additionally, it can do so in an incremental manner where only newly written data compared to a reference snapshot that exists on both systems is serialised.
I don't know how your tiles generation process works but if it works in a differential manner where only new/changed data is written to disk, this could be incredibly useful. If the tile creation process overwrites everything however (even with same content), this would not work as the diff would be the entire thing.