IOC can be very confusing until you fully understand it.
Also one of the modes will stop functioning when your MC gets within 10 meters of its original launch point.
Remember that in Home lock, pulling back on the right stick brings the MC back home.
Course lock means that the typical front of the MC, i.e., red legs no longer have to be the front. This is handy for aerial video work where you want the camera to aim sideway while flying forward.