Firstly, I think you have understated the positives of knowing the precedence table somewhat.
Secondly, even with the weight of the three positives you have mentioned, and no one is claiming any negatives to learning it. So the question is do the positives outweight the time investment of 2-3 hours? For anyone reading this I would say the answer is almost always yes.
I think my original statement has become a little side-tracked. My meditation is to memorize the precedence table - something a lot of us (even some of the best programmers) have not done.