Nationwide requirement for CDL when driving/towing over 10k?

In the land of CDL there is no Air Brake Endorsement. There is an "Air Brake Restriction". That is all Classes of CDL are "restricted" from operating air brake equipment unless the testing standard of the home state is satisfied for removal of the restriction.

Driving out of class is also a state level thing both on the CDL and non-cdl side of usage. Each state dictates their own licensing requirements. YES, on the CDL side there are minimum Federal Guidelines to be met.