I see.
We use for instance:
query.addScalar("businessTotals", typeHelper.custom(BusinessTotalsArrayTypeHandler.class))

Since we only supply the class, we don't have a way to have different instances for the UserType hence the UserType class name defines the equality value. For our use case that is. With our limited knowledge, we could not think of a use case where it would make sense to have different, unequal instances of a UserType. For our understanding, can you elaborate on such cases?