i get tired of this isn't fully britney etc. even gaga has backup singers in her songs so has ariana and more. get over that aspect it's nothing new in the industry. myah hasn't been involved since the glory project took off 98% is britney in the whole glory era.
if the story can’t be told with the use of a real authentic autistic actor you might not want to start filming in the first place it will always cause the wrong representation in the end and not the real deal.