While HC-tree looks promising, keep in mind the very first sentence of your link This project contains no code stable enough to deploy. The database backend

While HC-tree looks promising, keep in mind the very first sentence of your link This project contains no code stable enough to deploy. The database backend works well enough to run some test cases, but is still quite incomplete. Link to shortcomings, some of which are significant https://sqlite.org/hctree/doc/hctree/doc/hctree/index.html#status https://sqlite.org/hctree/doc/hctree/doc/hctree/index.html#s...