It's a perfectly reasonable argument. If it wasn't readable onscreen with the technology that existed at the time it was made, then it doesn't count. If we want to assume that EVERY graphic ever shown on screen EVER is somehow canonical, then we will really be opening up a can of worms.
Exactly. And, I believe, a giant mouse on one of the lower saucer decks. Be careful what you want to make canon . . .
Bleh, I don't need blurry distant shots of the Dreadnaught class to canonize Franz Joseph. The closeup shots of the deck plans they use to home in on Mcoy's location are good enough. One page is as good as the whole book just as connection to one episode in a crossover is good enough to link the two shows.
What about the Captain's Whore? Well, they had a different word for it in that TOS episode, but all I can think to call her is the Captain's Whore.
The Enterprise-D has a dolphin tank, a hamster wheel, toilets, and all that fun stuff according to blurry on-screen maps. Actually, I think Deanna or Geordi mentioned the dolphins once, so that makes them like double canon.