I don't know why Beretta would recommend against the use of +P ammo in the 92 Series when the M9 variation served in the US Military for a decades being fed a steady diet of hot NATO Spec ammo, and shared the same exact frame between both the 9mm 92FS and .40 S&W 96FS, unless your friend's Beretta 92 is an older model 92S/B.
Regardless, +P ammo is in every practical sense a worthless novelty that only adds a measly 10% increase in performance at best, in exchange for wearing out springs at least 25% faster and can potentially damage the firearm if you don't upgrade your springs.
Frankly, if Standard Pressure ammunition is insufficient for your purpose, then so is +P, and you're better off upgrading to a more powerful cartridge.
Also, not to spark a caliber debate, but 9mm Luger generally isn't considered a viable Wilderness Defense cartridge. Most folks recommend .357 Magnum as a bare minimum, some won't even go lower than .44 Magnum.
Personally, I say that if you're going into the wilderness where dangerous predatory animals roam, then you pack the most powerful firearm that you can possibly manage to shoot accurately, focusing on cartridges with the highest probability of stopping an animal in a single well-placed shot, since animals tend to be fast enough that the most you're likely to get off on an animal who sees you as prey is 2-3 shots if you're lucky, so capacity should play second fiddle to muzzle energy.
If I were going into the woods, then I would carry my Mossberg 590 Shockwave loaded with Brenneke Black Magic Magnum slugs.
Or if it had to be a handgun, then I'd make it my H&K USP45 Elite loaded with 230gr .45 Super.