RTree-enabled Mono.Data.SQLite for Android Mono/Xamarin

For a geospatial Xamarin-project I need SQLite/RTree-enabled.

With Mono.Data.SQLite it works for Xamarin.iOS, but not for Xamarin.Android (exception unknown module 'rtree'). Seems like Mono.Data.SQLite is just a wrapper into the sqlite-lib of the OS and Android doesn't have rtree enabled but iOS has.

So I thought, why not compile my own version of the Mono.Data.SQLite with RTree-enabled ? So I tried system.data.sqlite, but this is again only creating a wrapper with no chance to enable RTree.

This is unfortunately beyond my skills, but should it not be possible to compile a dll for mono from system.data.sqlite-sources which is not just a wrapper, but also contains the sqlite.dll stuff with rtree-enabled ?

Thanks for any help in this.

Tom