Squadron level 60

Hi
I am wondering what is there to do with my Grand Company Squadron after having them all at level 60? I can't advance more?

you get them some handy chemistries to bring back things like MGP/Gil/Materia/Scrip and your personal tier III buff items and that's about it. also if you want to advance to the highest rank so far in your GC you're going to need to run some missions with them.

Thank you for the reply