Nice one @john.howitt Just looking at the right arm position. Can you try experimenting with playing the thumb strokes an inch or two more centrally in the bass so directly over the pickup. That will naturally angle your right arm slightly differently and I’m wondering if that will feel like the arm and wrist are supporting the thumb better. Try that and see if it feels any more or less comfortable and whether it affects the tone at all

Okay, thank you Edd!