This is a much more seamless solution that what OP is using (for both his project and for users)!
@_neil, any reason not to use this instead? duckdb over a .db file is a more straightforward approach
It seems like you still need to export the database here, so maybe same amount of steps since duckdb can import CSV files directly as well.
I think supporting the native Apple Health export feature would be a good idea. It just takes longer than the CSV export, so I started there. I would imagine the native export has more data, though, which might be nice.
For getting Apple Health data into duckdb, I’ve used this in the past: https://github.com/dogsheep/healthkit-to-sqlite. (You can load the SQLite database directly in duckdb.)