Here in the hot Georgia weather, where shorts and T-shirts are the main form of apparel, my R9 goes just about where I go, no pocket printing nor does the weight of the gun pull shorts down.
As for ammo, I’ve found that my Rohrbaugh loves either Speer Gold Dot ammo, or 147 gr. Black Talon, (although not readily available ammo & a bit expensive these days, I still have some Black Talon that was our regular round on the PD some years ago).
My R9 also has a liking for just normal FMJ ammo.