Most +p+ LE ammo is loaded very close to the NATO spec.
continued use will not damage a Glock, Beretta, SIG, HK or most other modern pistols. That's the pressure level they were designed for.
I load all of my 9mm practice ammo to +P+ velocity specs. (I have no way to measure pressure) Thousands upon thousands of rounds have not caused any wear on my SIGs, Beretta or Glocks
And BTW, this is the same ammo spec that was considered."standard pressure" in Europe during WW2.