The DOT does not approve anything. They are not a policing or enforcement agency. They create and publish a list of specifications that OEM and QVM must adhere to in order to sell their vehicles to the public. It is up to each company to interpret the specifications and build their vehicles and all parts used in them to the specifications. There is also no legal or illegal aspect to the specs, the item adheres to and meets the spec or it doesn't.
If it spins, it can be balanced, you may have to get creative with how you attach the weights but they can be balanced.