Hot seat time, but for the very first moment when the game starts only and to all players: "map awareness starting round time".
For example, you can set only five seconds of standard hot-seat time, but 30 seconds for the very first moment when the game starts to all players. All players must wait those 30 seconds before the first player starts playing with it's hot-seat time.
Hot seat time, I believe, has its name because when you are playing offline with friends, you need to leave the chair that is hot to your friend sit and play. So for this feature hot-seat time is not the ideal name. I think "map awareness round starting time" would be a good name for this.
Why such a feature would be good? Because there are many games that in the first turn, players make stupid decisions because they are not aware of all the positions, the order of the worms, the possibilities of plays and start playing with little time to think. This is not good for strategy and high level of gameplay. Also, if there's a player with slower internet or connection that arrives in the game later and starts playing Elite which has zero seconds of hot-seat time, this player has little time to think while the other players already thought on a lot of possibilities while the player was still loading the game to join it.
I know, who starts usually has an advantage most of the times, so this situation can counter the advantage of the one who starts, but I still think a scheme option of this idea would be great. This way, all players would be able to equally have some good time to look around the map, analyze all the situation and possibilities before starting to play. If the scheme doesn't need this, you can simply start with zero seconds of "map awareness round starting time".
EDIT: this feature would be great for races with big maps where usually players only have 10 seconds to find the start and often position their worms at a wrong place. It would be good for people who host new schemes, so that they can explain the rules, settings and details, the important stuff, while players can see the whole map and things they wouldn't understand so well explaining in the lobby. It would make things easier for everybody.
EDIT 2: An optional sub-feature would be that during this time, only the host would be able to control the cursor/pointer to point things on the map to explain stuff. He/she would be able to click with the cursor, but it would result in that "dud"/negative/"you can't do this" classic sound of the game.