I have not visited this gambling website till now. But I don't think there is any need to stop auto bet when switching to other tabs. Users make auto bets on their own will and without any force. You can also add stop loss to stop the auto bet once the balance becomes lower than a specific amount.
Yes you right, i did visited and played auto dice, look nothing button to stop lose and win game. I did winning about 3x from my balance just leaved 10 minutes. i don't know how that machines managed my bet when don't have to stop lose/win button.