The Safe-t-plex coating is just another acrylic roof paint. It will make your roof look clean and help to shed debris. It has barely any leak prevention. Really, leaks happen at joints and seams, not through the membrane in almost all cases. You would be better served by using Eternabond tape or Dicor sealant and buying roof paint at the big box stores.
If you want a functional roof coating system, the Line-X or similar truck bed coatings will give you protection against leaks.