Then you don't need WAL. I didn't say replication isn't possible, I said "that's not how it works."
A bunch of different people solved this already (though none in a couple of weekends); common to all of them: they don't use WAL mode.
> The shadow WAL is a directory next to your SQLite database where WAL files are effectively recreated as a sequence. . . These WAL files contain the original WAL frames & checksums to ensure consistency.
https://litestream.io/how-it-works/
> (though none in a couple of weekends)
As I said, getting sqlite in wasm to run in WAL mode such that we could start to implement replication, like for example how litestream does. Not this strawman you build, of implementing replication.