4. The Chance To Meet His Science Heroes
At its heart ' Doctor Who' was intended by the creative team of Sydney Newman & Verity Lambert to be an educational programme- the great & good of science/history presented in a whole new light. Indeed, inside a giant Time Brain if the Rani had got her wicked way with geniuses like Albert Einstein & Louis Pasteur. But I think it would be a nice gesture at least were Cox's Thirteenth Doctor to get the chance to meet the men who got the universal wonderer into science in the first place. Richard Feynman & Carl Sagan are among the notable names listed in this regard on his Wikipedia page, and it would be a start if nothing else, I'd argue.