When the dealer shows an Ace, all players should have a chance to place a "side bet" for insurance, just like in real casinos. If the dealer has Blackjack, the bet pays 2:1 (max bet being half your main bet).
If the dealer has Blackjack, but the Ace is the under card, then everyone simply loses just like it is currently programmed.
We decided not to include the option for insurance as it is traditionally a losing bet for the player. As with all side bets, it is a bet that heavily favors the house.
While as a general statement, this is true, it all depends on HOW the player utilizes it. I.E. I only buy insurance if I have 20, thus greatly reducing the odds of it favoring the house.
Please reconsider bearing that in mind. You could put a confirmation box asking if players are sure before choosing to insure a weak hand.
More to the point of the dealers winning blackjack in the first place, ask yourself this question?
Why does the dealer get 10 for his first card for 90% of hands dealt in blackjack?
Because its rigged so house wins 75% of bets made, it was same on home - A CASH COW!