Hi Arjen,
You can disable it with this command:
W.init({ waitScreen: false });
However, I believe this will disable all gray screens, including "waiting for other players..." So, you could handle this manually, e.g., by calling at the right moment:
W.init({waitScreen: true});
W.lockScreen("A player disconnected...")
setTimeout(function() {
W.lockScreen("A player connected") // after a while, this is your BOT
W.unlockScreen();
W.init({waitScreen: false});
}, 10000);
This needs to be executed on the client side, so you might have an event listener for those commands.
It is also a bit more complicated, because you would need to kill the timeout if the player reconnects.
Let me know if you have any questions.
Cheers,
Stefano