"BB states it’s +P ammo is within SAAMI specs. SAAMI 38spl + P max pressure is substantially lower than SAAMI 9mm or 9mm +P max service specs".

That's right, and all of them provide adequate power.
Standard pressure subsonic 147gr 9x19 gives me an average of 952 fps and 292 ft-lbs out of a J-frame. That hurts my hand enough in a 12 ounce gun to be plenty of power for my purposes.

The wisest use of our money is anything that pleases us.
I choose to spend some of mine on guns and airplanes. Makes me happy.