I play a Fender parts P-bass. I used a 4 inch wide nylon/neoprene strap. Left to its own devices, my bass likes to hang at about a 33 degree angle. I play at a 45 degree angle or greater. For a short period of time, I can hold the bass at a 45 degree angle using the palm of my plucking hand and thumb on my fretting hand. But this causes discomfort and cramping after about 20 minutes.
I tried relocating the lower strap button up a few inches, and that did not seem to have much effect.