[Geof Gilland] “… but will this help with keying because of the nature of DVCAM pixels?”
No more than if you ask your talent to stand on the wall instead of the floor.
If you think about it, your camera will just see an image and not care whether it’s right side up, sideways, or a shapeless blob.
Now if you shot DVCPRO50, with a higher data rate, that might make a difference.
Steve