Its an interesting idea, but I think more complication than it's worth. I would not want all the extra lines cluttering up the tramp, especially right in the area where the skipper is going in and out on the trapeze. I suppose you could put a grommet in the tramp and run the lines underneath, but I still think this system is more complex than it needs to be. We rarely adjust the position of the jib cars. Occasionally in high wind we'll move them back a little, but most of the time they're always in the same spot.
My advise would be to determine the cause of the jib car locking pin not working propery and fix it. Replacement jib cars are fairly inexpensive (I'm talking just the car, not the whole block).