I feel your pain brother! I went through the same thing, trying to find the most comfortable position to play. After a couple months of discomfort, I finally decided to use a two strap system like the one use on two and three row accordions. It has worked better than I hoped. I don't need the thumb strap at all and am able to slide my thumb up and down the keyboard as needed , just like I would with an Irish accordion. My wrists are always straight eliminating stress and pain, and because of the second strap, stress on my left shoulder is greatly reduced because the accordion is stabilized by it. Though a bit unorthodox for Cajun accordion, this setup is very comfortable for me whether I am sitting or standing. The accordion is always in the same position.
Thanks for the strap info. At this point I'll try just about anything.
Jammin' with Jonno? Me? No. That was Dub Deshotels if memory serves me Budweiser. I spoke with him afterwards and got a rather cold shoulder from him. He didn't even give a camp. He drove in from Marksville and obviously had other things than accordion playing on his mind. I just about got a contact high from his breath. Turns out he does a lot of K2 and hard wine. Me, I personally smelled more like smoked meats and spilled beer. But at least I don't smell like I'm hurting myself... you know?