Can crafted mythics have multiple GA’s?
Yes, but it’s gonna be rare. During PTR people constantly made batches of Mythics to get 3 and 4GA items and sometimes you’d drop hundreds of a Mythic before getting its 4GA version. 
Can crafted mythics have multiple GA’s?
Yes, but it’s gonna be rare. During PTR people constantly made batches of Mythics to get 3 and 4GA items and sometimes you’d drop hundreds of a Mythic before getting its 4GA version.