And to address your other question: my local water pH comes in at 7.6. That generally means I end up adding about 5 cc of lactic acid +-2 depending on grainbill, style etc. I plan to try phosphoric at some point, but I'm not a "supertaster" apparently because I can't taste lactic acid, BIAB beer differences, or other subtleties. So I have plenty of lactic acid, plan to use it, and like the results.
I recently started aiming for a mash pH of 5.3 after hearing a John Kimmich podcast.