You may already be aware, but SQLite 3.40.0 was just released this morning, and it adds a beta release of an official WebAssembly build.

https://sqlite.org/wasm/doc/trunk/index.md
Changelog: https://sqlite.org/releaselog/3_40_0.html

Your library likely still has some value-added features over using SQLite directly, but it might allow you to simplify this library a little bit?