When I try to create loops with carriers, it gets very confusing on the screen. One idea could be to have the loop path a different color than the rest of the paths on the screen when you are editing the waypoints. When ship paths intersect that have loops, the map gets very cluttered and you can’t see clearly where the ships are heading.
Also It is impossible to create loops with ships unless the ship is already at the star. If it is in between routes, you cannot make a circular route. It would make things a lot easier if you can loop back to the ship instead of another star and make a circular loop with the carrier.