The PTR grading is based off the top ten(?) winners' stats at the selected level. The problem with that is many of the top winners at .10 NLHE multi-table and play an entirely different game opposed to 1-2 table players.
I would pay little attention to the grade itself. There is some advantage to making minor adjustments based on them. However, basing all your adjustments on them is hap hazard. Play solid poker and forget what works for everyone else. Find your own style and tweak your plays based on your opponents, NOT what the numbers tell you.
Pay attention to the common mistakes at those levels and capitalize on them such as over playing weak aces, min betting as a bluff, playing mid range hands out of position, over playing moderate draws. Those are but a few common errors made at those stakes you should learn to exploit.
PS. PTR may be a violation of the TOS for your poker site
. I know for a fact using it as a Pokerstars player is a violation and subjects you to a ban from the site.