Balanced tires...

Some tire brands are a pain in the *** to balance, Mastercraft being one of them. It also depends on the type of machine being used, the ones that simulate road force would be the most accurate, some shops might only have a dynamic balancer. Tires need a load on them to find their happy spot on the rim so after driving on them for a few miles the balance might be off a little.

Balancing trailer tires is a waste of time, you wont be able to feel any vibration from an out of balance trailer tire unless your riding in or on the trailer.