I came here for a technical discussion of MUM, but your comment just triggered something: my wife and I pay for ad-free YouTube (part of the music bundle). As a paying customer, I just don’t understand why they would annoy me with showing videos that I have already seen. A better UI would be a top level menu option to show history of watched video (and search writhin already watched material). Then the default page could remove already seen material.

I am a happy paying customer for GCP, Play Books+Movies, etc., but I think they need to step up the quality of their services for paying YouTube customers.

Thanks for your comment.