Actually, the point I was making is that a rules lawyer could object that play hasn’t begun until white has made a move. Regardless if a clock is running or not, or if the round has officially started or not.
Time is split if both players are missing because play hasn’t begun yet, and time is split if no clock is present because play has begun. If anything, it shows that round start, play beginning, and clock are three separate issues.
Though I can certainly agree with the idea that the start of round time is when play begins, regardless if a move has been made yet. So would I object such way, or support it? No.
In your second example (and in the case at hand,) I wouldn’t rely on 20b. I’d rather suggest it’s a violation of 20a, as it simply shows poor sportsmanship.
But either rule is made pretty moot if the TD simply allows the player to walk away after declaring they are off to study the other players’ games, without objection.