I wouldn't have really liked that, anyway - "in-jokes" like that almost always take me right out of the book (Peter David, for all that I've liked his books, is particularly egregious in this regard). If there is going to be a reference like that, I prefer the way Christopher
did it in Ex Machina
, when McCoy sarcastically calls Chapel "Mother," to which she responds, "Honestly, Leonard, do I look
like someone's mother?" It was subtle enough that I missed it completely the first time I read the book, but funny enough that I laughed out loud when I read it a second time.
As for crossovers, I always thought a Doctor-Who
crossover would be interesting.