Using 12 Motors on APM 2.8

Hey, an Ardupilot newbie here. I am working on repairing an old drone (3+ years old) used at an ASME competition at my college. It has 12 750kv motors spinning 1145 props and uses what looks like an ancient APM for a flight controller (no case but the pin layout looks similar to newer versions). It has two motors mounted on each arm with one sitting above the other, like an X8 but with 6 arms. I am interested in updating the drone’s FC to 2.8 but I am not sure how to configure the motors as there are only 8 motor output ports and no options in the wizard for this type of drone. Is it possible to use the gimbal servo ports to control the other motors? Whats the best way to configure a drone of this size with Ardupilot?

Set it up as a y6 with 2 escs per motor channel.

Join top front right clockwise motor to bottom front left clockwise motor etc

Thanks for the tip! ill give that a try.