That’s actually a fascinating idea. All interstellar travel is based on the movements of the planets through space time. I bet it alternates between being technically faster and slower than FTL travel since you may have to wait for a time when your destination to pass into the planets past location.

Wow that’s a fun thought hole. Constraint certainly breeds creativity!

If you can get into it, and more importantly enjoy the role, also can be hilariously well compensated.