Coming from a relational database mindset, it seems odd that one only one one graph db per instance of neo4j. Is the idea that we do multiple subgraphs starting from root ?
If it is only for development, you can use neo4j-instance, it helps me work on several neo4j databases at once (at the same time, basically setting each on a different port), and it flows a lot better than adding a label to differentiate between different schema, or prefixing nodes with the scheme name. Since, you do not have to change how you interact with the neo4j databases because they are still separate databases on different ports.