Any work I have done on my own project for the last two days has been spent on paper.
Adding SQlite to manage my flatbuffer data, works in minor conjunction with the file system. Basically, all my tile library collections would go under a content folder, where you each collection of libraries goes into its separate folder and there you would find your library.db files that store all the flatbuffer objects.
Taking all the flatbuffer objects within the library that are larger than the 64k in size and caching them in separate files on disk, since the size of the blobs do matter for read and write speeds.
The construction operations are stored in one .db files, the cached solid objects in another and the final resultant polygonal mesh in the third. Since the most current polygonal mesh data is stored in the brush that is being used to blit the geometry into the scene, I would assume that this db setup for caching the computed results should be enough. Simpler design and setup is always better.
And since my interface is mostly just .json strings to pass commands the the builder, it would not take much to have the whole interface work through .json commands and then expose it through websockets. Receiving commands and sending back flatbuffers of polygonal mesh results.
Anyway, … I need sleep.