Things I consider are
Is my ph in range to get conversion?
Is my ph so high I might extract tannins?
Am I adding enough lactic for it to be detected in the flavor?
Boil ph, so I've read, plays into break, hop extraction and quality. But I think that if I've not seen a problem there, I'm not going to be a hypochondriac about it.
I feel ph is most important in the mash tun and then in the glass. So I can hit 5.5 in the mash tun with minimal acid. Then I can test final ph by meter and taste, and decide what to do about it then.