I can’t say whether 13 is too hard or not, but the point of the change was
It’s not supposed to just be a freebie. You have to create the situation for it to occur, and might have to give up a quad-match for it. If they wanted you to get the conditional effect every time, they wouldn’t have made it conditional.
I think people are misinterpreting this:
The 80% doesn’t refer to instances of you casting the spell, but 80% of the instances in which you try to create the circumstances in which you’d get the conditional effect. In other words, if you’re not actively engineering those circumstances, the conditional effect will be a very rare event. If you are trying, you’re only intended to succeed 80% of the time.