I like the idea of being able to narrow down what you get from the wheel by choosing what to sacrifice, but I think it would be nice if you could choose specifically when and where boosts would activate . . .
For example, if your population is at maximum and you got (randomly) the Yaxa spell, it wouldn't do anything.
But, if the Yaxa spell were temporarily "stored" so that you could activate it when you want (and maybe in the city you want?), the bonus wouldn't be wasted. (I'm thinking bonuses could be stored maybe in the moon temple, or next to your profile picture like the blessings, or in the shop menu, or in the Tzolkin menu, or somewhere else)
While this would probably be difficult to do, I think it would be nice to have it so that you can always use/benefit from what you get from the Tzolkin wheel. But that's just my opinion (and I don't even use the Tzolkin wheel).