My comment wasn’t about the maximum time; it’s about the minimum. Imagine it’s in season and I own, say, Verlander, and he’s scheduled to start tonight. I have a pending trade offer for him. I want to know that if I click “accept” at, say, noon today, he is still going to be on my roster for tonight’s game. I wouldn’t like the uncertainty of wondering whether a bunch of prompt “approve” votes were going to cause Verlander to leave my roster before the game starts.
Maybe this is a bad example because I could just wait until after the game starts to accept the trade. The larger point is that because lineup management is often so precise in Ottoneu (lookin’ at you, Mr. 1530 Club), introducing uncertainty about when a trade will be processed seems undesirable.