I am always experimenting. My current coco run I'm mixing it up a little, been using PBP for veg & bloom, with boosts from
Big Bud and Koolbloom (both powdered and liquid).
I would
like to see the pH of my run-off much closer to what I'm putting in. Unfortunately, due to some family stuff happening right before this run was put into flower meant that I had to rely on my husband and my son to care for the girls. So I had to really simplify the recipe and reduce their work, so I had them mix the RO/DI water 50/50 with tap water. Big mistake, because our well water is that hard & alkaline. Means I am forever battling what's become 'locked' into the coco from the well water, which drives pH and alkalinity up (alkalinity as a measure of buffering capacity).
But to give a very short answer to the last question, I don't think I'm having or creating problems by letting run-off pH go where it will, but I also honestly think I need more experience under my belt to give a more definitive answer.
I hope that makes sense.