Hi, how about a lock button on top of every slot box?
It wont make it that much easy the game to play, but may increase the chance to win some card, also, will help in not verbally abuse the computer from time to time when seems you will never get a card out of that thing
The way the slot machine currently works, this would not help you, and has a good chance of actually hurting you.
When you win a match, the slot machine chooses 5 cards from the deck you beat (it tries to avoid towers, but if it cannot get other cards, you may see a tower in the spins). It then spins those 5 cards in each wheel. For the SECOND spin, it chooses 5 NEW cards, and spins again. And 5 NEW cards again for the 3rd spin.
If you were to "lock in" cards after the first spin, there is a chance that the card might not be selected again in the second or third spin. If it is not selected, it is impossible for you to win (because nothing can match the card you locked). You will have actually worsened your situation.
Also, I agree that AI5 is about the worst for cards. AI5 will test your gameplay and decks, but if you want cards, try AI3 (unupped), T50 (unupped/rares), and FGs (upped).