David Prowse was decades too old to play Anakin when they filmed the documentary. It’s not an option, even if it was available.
I agree but yeah, Shaw was also to old.
However, if this was to be done in any edit, I done think its a good idea to use the documentary footage either. The only way I think this would ever work, is with a Tarkin level cg Prowse and a deepfake, but that even more of a pipedream for this decade. 2030 though…?