I finished the 16 oz of probio and deep cycle. I dosed it over the past 3 weeks and more occasionally than the instructions recommended. Figure I'll report back on my experience. Just a subjective take on my end with it, not really a controlled experiment, so take it with a grain of salt.
Overall I think it did improve my water quality and clarity. I've noticed my water got visually cleaner and more crystal clear. The skimmer now pulls darker (black instead of green) skimmate without increasing thickness. So there's definitely some changes I've noticed to the skimmer performance, personally I think it's a positive one. I did have two acro frag that RTNed recently but I don't think it had to do with the PNS. It also reduces the rate algae grow on my glass, so I need to scrape less. Overall the corals seem to be doing better after seeding it with the bacteria, likely due to the water quality improvement from it.
I have high NP level all the time (N 30+, P 1-2 ppm), so it's hard to tell if it made any impact to the NP level.