Transporting the tracks loaded is not good for them, but assuming there is nothing wrong with the design of the particular system you are looking at, it is not going to be ain immediate problem so much as it is going to be accelerated wear.  Not a lot different then what you see with the narrow tires.  The military runs Challenger-type belts cross country at low convoy speeds.  Their idea of acceptible life may be different then ours, however, as they also run metal tracks cross country at up to 50 mph. 

On a 40' implement I would not lose any sleep over th scribbing when turning.  Sort of like the track tractors and "berming"....you can make it an issue if you want to bad enough but from a real-world viewpoint it's a non-issue.    Our grain carts get turned around in a 16 row wide hole through the field when they need to to catch a combine opening up.    They have full length large Challenger belts on them.  It scuffs the ground but it's not leaving something that the sprayer is going to notice next year.  They can be turned that short loaded but it will make more of a mess of the ground to do it.  

I think it's a good idea.  Cost is the only problem.