what is the current graphql-java version with stardog?
In Stardog 7.3.0, we updated to 14.0. Have you tried it since then?
It looks like the NAME production in the parser is what is going to be limiting here and it's still only latin letters and arabic numbers:
I made an attempt to change the Antlr grammar in the Graphql codebase but could not get it to work. It might be worth asking for help on the Graphql GitHub repo if you're still interested in customizing this. Stardog is passing everything down very transparently so simple replacing the jar should be sufficient once the Unicode handling is fixed in Graphql.