one fascinating aspect of Dr Who as a sprawling multimedia uhhh... thing, is the way different corners of it follow very different meta-narrative rules and conventions, to the point of there being a spinoff that is explicitly an in-universe warped parody of the series.

you wouldn't look at something like iris wildthyme and think that it was spawned by the same world that brought about torchwood. you wouldn't look at faction paradox and think it was woven from the same cloth as the sarah jane adventures.

i genuinely cannot think of another fictional universe with such range. even ignoring spinoffs, the VNAs bear little resemblance to the version of the show onscreen in the 60s, and, hell, that itself bears little resemblance to, say, the version that aired in the 80s

and one under-explored thing in multi-doctor stories is, i feel, the sort of tension that comes with bringing together stylistically different eras. the only attempt i can think of is twice upon a time's rather clumsy jabs at the shortcomings of 60s media, which don't quite work

(it's a classic case of Moffat's reach exceeding his grasp, seeing a potentially great idea but unable to realise it in time for it to make it onscreen. bit of a theme in his writing)