First off, never take your tire gauge readings as gospel, almost every gauge will read differently.
Secondly, you always carry more weight on the back axle(s) than the front so tire temperatures and pressures (over cold inflation pressures) will increase more.
Thirdly, I would never increase cold inflation pressure over the sidewall rated maximum inflation pressure. Tires are designed and marked with that pressure for a reason. Tire manufacturers know how much a pressure increase will be and factor that into the tire design.
Finally, as long as you can place your hand on the tire and it don't feel uncomfortable, the tires are fine.
