I wouldn’t want that. Besides, from my understanding, the 16:9 are cropped 4:3 anyways, so it still would be rather noticeable
I’m not sure what you mean by “the 16:9 are cropped 4:3 anyways”. On a 16:9 laptop monitor or TV, the BR footage is full screen, whilst the DVD footage has black bars on the left and right (as it is 4:3). The switch between BR and DVD footage is therefore quite noticeable. As there’s no way to make the DVD footage 16:9 (has not been released by NBC or whoever made Friends), the only way to make the output image ratio consistent would be to crop the BR footage. Ofc, OP can do what he likes, just my thoughts on this.