Hi @dt1,
You are currently in the gds section, I have transferred your thread to the more appropriate cypher section in case someone knows how to optimize your query.
That being said, you are welcome to have a look into gds's shortest path algorithms. They work on an in-memory graph so once projecting it could potentially run faster.
Let me know if you have need any help with these GDS procedures.
Best regards,
Ioannis.