Do you mind me asking, what kind of problems did you run into with Neo4j? Did you encounter performance issues after the DB grew to a certain size, or did you realize that the data wasn't suited to a graph DB and weird query patterns started causing trouble, or was it something else entirely?

I'm considering using a Neo4j self hosted instance for a project, but having only played around with it in low-stakes + small-data toy projects, I'm not really familiar with the footguns and failure modes...

All that aside, plugging holes in a sinking database for six months because you can't come to a descision does not sound like a fun time :D