Yeah, a student got it working prior to seeing your response. When I asked, I got this back in regards to how he got it working.
Used this https://www.youtube.com/watch?v=58XWVDnB7Ss to get understanding and how operation of the controls work.
Then found this Relay ON/OFF for lights control out of pixhawk to get started. Lead to updating the Ardupilot version. It gave the start to setting the relay function on the servo port on the navigator (yes the board in the video is a pixhawk but it still used the same set up).
Then found and used this https://bluerobotics.com/learn/connecting-your-device-with-navigator-and-blueos/#outputting-servo-and-relay-signals to finish setting it up for controlling them. Finally used Cockpit relay commands after the Ardupilot parameters were all set up.
I did take your suggestion and the parts were ordered from Amazon for the students to test next week.