Do you agree that as a result, you have Unauthorized Information, and you must carefully avoid using that Unauthorized information (and that "what I always would have bid" isn't carefully avoiding), throughout the rest of the auction and play, and that if I think it's possible you didn't follow that to the letter, I can call the TD to get an adjusted result? And do you realize that as the transmitter of the UI, you are *not* under those restrictions - and that it's not, actually, wrong to have to think about a hand?
But by "reserving one's rights" or "agreeing we have a slow call", you're asking that entire litany of questions, and probably more that I can't think of off the top of my head. But I bet there are thousands of bridge players who don't know what that "entire litany" is - and they're just going to answer the question asked. And that puts them in a disadvantageous position that is unwelcome (unless you're the kind of player who likes having those kinds of ethically dubious advantages - which I'm sure none of the people here are, but we all know one!)
When playing in the rare air of Flight A, one can assume that we all know the whole game. Others' club games may be different, but I wouldn't expect the C pairs to understand it all.
You mean that if they knew the consequences of telling the truth they'd lie instead? Perhaps some players would, but I'm not sure that we should have much sympathy for them.