Bill,
Honda uses those to attach to when shipping their scooters. Well what better place then what Honda uses.
No matter what you attach to... if you use to much force anything will brake. All that is needed on the rear of the scooter is just enough to keep the scooter steady and up-right and a high torque is not needed. Using the stock Honda transport tie down loops works just fine for that job so long as you do not come out on to great of an angle from the scooter.
I have seen 30,000 dollar Harley's BOUNCE right out of the back of a pick up truck when a nylon strap broke because of to much force put on them.
Firm and never to tight just enough to hold the scooter.