SQLx is great, but I had a long laundry list of issues with its SQLite support so I forked it into a focused SQLite-specific library. It has now diverged very far from SQLx, and the number of small inaccuracies and issues we fixed in the low-level SQLite bindings is well into the dozens. The library is unannounced, but is already being used in some high-throughput scenarios.
https://github.com/cortesi/musq