I have been playing bass since I was a teenager and throughout my playing career I experienced wrist pain from holding the neck up by pushing down on the body with my right forearm. I tried using two straps to keep the neck up, but that resulted in it being nearly impossible to get the straps on. Furthermore, when doing studio work, my neck was always parallel with the floor. This distorted my left hand technique and made it so I had to reach across my body to get to the high notes.
As time passed, I started fiddling around with a body design that would allow me to play sitting down while keeping the neck up and the body out of my way. I also wanted the bass to be balanced when standing, with the neck similarly elevated.
After a lot of trial and error, I came up with the solution modeled below:
As you can see, the position of the neck makes intonation easier and the high notes are available by just sliding my hand down the neck. No changing to "thumb position" like an upright player would do or reaching across my body.
Of course, I can still play "normally" when seated, and this comes in handy for when I want to use slap technique. Note that in both positions, my right hand is relaxed because my forearm isn't forcing the body down to keep the neck up.