To correct those technical inaccuracies about GsP braids for flyreel backing - thinner, I'm afraid is not better. The difs in diameter between the handful of brands with serious backing credentials are sufficiently infinitesimal as to not have any bearing on matters like water pressure on the tippit and recovery rates. The downsides for braids that are thinner for a stated breaking strain is that they actually have less overall tensil strength that those that are a thou' or so thicker. The number of "picks" per inch of weave is another factor. Too many (the tighter the weave) the weaker the line, too few and we're back to the awful handling hassles we had with first generation braids. Pick densities vary between brands. Thinner diametres also mean a greater vunerability to the knocks, bumps and wear that comes under the general heading of abrasion resistance - braids' Achilles heel. Colourwise, hot pink offers the best combination of angler situation awareness and (in) visibility to fish.
With every dealing we can possibly have with abrasion resistance, regardless of whether it's tippet or backing, the foremost "anti" factor is the diameter of the material. At this juncture in lines development, the capacity to spread the load counts for more than smaller diametres that might contain snake oils or genuine toughening ingredients.
Harro