We will eventually add a public async API to .NET Couchbase Lite. However, I'm not anticipating any changes to the SQLite lib that we use.
For one, I don't see any evidence at the moment that changing will make any significant difference, but changing would certainly delay our progress. It's possible this stance might change after going through the process of performance optimization, but
such a change would be driven by clear evidence from test outcomes.
Second, there are very few SQLite PCL libs that meet all of our criteria, the most essential being support for custom collation functions.
I believe the biggest gains won't come via changing SQLite libs, but instead from other areas that I know can be improved.
It's just going to take a little time until we get there. If you find something that you feel does help, please send a pull request and we'll certainly review it carefully.
Sent from my iPhone