1. For a new tank, start with substrate sauce.
Also FYI, PNS ProBio is actually not a coral/invert food primarily. Thats PNS YelloSno. PNS serves several functions you can find on its information page on algaebarn.com. For very in depth article, I can't remember pns's parent company, but google/find them and there's even more information.
I believe these products have been key in helping me to go no water changes.
They recommend 1.25ml/gallon of PROBIO, and 1ml/gallon of yellosno. And using this system daily, but alternating product every other day. (probio day 1, yellosno day 2)
Once tank is developed, I would only use substrate sauce when your phosphates are running very low, as a kind of phosphate dose. PROBIO can get phosphate lower then you might want. 1 dose of substrate sauce raises phosphate by .03. But substrate sauce has several other benefits as well.