Hey i have a suggestion! Can you make NPC's that will drive cars/planes/bus. Idea is that you Will go i to a car/plane/bus and the you Will put command like /rec and the every move of vecihle Will be recorded. After making a loop with bus or a flight from Point A to B and from B to A (also loop) you will put next command for example /stop and the record Will be saved maybe in mods or .minecraft folder. After that you put special NPC in car/bus/plane and choose the record you want. NPC Will still drive that what you recorded before. Maybe you can stop the NPC driving with command.

If you add this features please add this also in 1.12.2

Hope you enjoy this idea