Hey Nick,
I might understand that someone would rule it in another way if this happens on a regular casino tournament because you probably need customers to be satisfied, but I work only on multiple days events. Most of the players are seasonned and some are pro players and they want the game to stick to the rules and this the way I want to satisfy them.
Players are supposed to pay attention to the game, if they want to watch their favorite show on their ipad, it is a call they make.
Also, by allowing a bet to be withdrawn from time to time you do not reward players who are actually paying attention to the game.
So in heads'up case, throw only one chip is always a call whatever it is an undersized or oversized chip?
In situation 1), if we have another player calling the 20k before the player throwing a 1k chip, the latter could complete or surrender ( but force him to complete the big blind)
Am i right?
I think I would pay attention to which street the action happens.
If it's on a river and the 1K player is the last to act before showdown, it could be a trick to make the other player to show their hands and use the undercall rule at his advantage to avoid putting the 19k chips overlay. (It is not fictionnal, case happened in Paris last year)
If this is another street, and the action has been frozen by the dealer, I would rule as complete/surrender. But if this is an all-in situation and 1K player last to act with no further action possible, It would be a mandatory call.
In the case 1K is less than a big bling and the player want to surrender, he would have to surrender a full big blind bet. It makes sense to me.