Correct, but the earlier ones used gravity turn. My comment still stands. The final payload stage achieved correct orbit, as I stated, with an IMU and RCS, as you stated. It depends on how accurate you need the orbit.No, the final stage Japan Lambda-4S had an IMU, controller, and RCS.
https://open-aerospace.github.io/Lambda-4S/overview/gnc/
Edge case anyway, don't get too hung up on it .