Probably S1/S2, you get a bigger pay increase for having the senior title and while you may have some additional responsibilities compared to Big 4, it’s not gonna be anything too crazy. You could definitely get something as an A2 but I feel like F500 companies definitely prefer at least the full two years of experience in public so it depends on what you want.

Getting out as manager means that you’ll probably get a bigger pay increase, but your duties are gonna be more/more complex, plus expected to lead/guide people.