I appreciate it when people scrutinize my work; it helps me to see what I may have overlooked.
Tp4tissue- I understand your concern about the ball placement but in this case it's unwarranted, at least for me. I use the tray at a roughly 10-15º negative slope. This prevents any wrist extension while using either the keyboard or tray. I should know; my right hand only extends 15º back and is painful with any extension. That is why I have modified trackballs into trays in the past. Also, the tray allows me to keep the keyboard from being too high which is something to be concerned about with tenting..The concern I initially had was that the arcade buttons ended up being higher than what I thought optimal, however after a few days of use I pretty much forgot about that. What took me longer to adapt to was the center placement. I remember early on thinking I made a big mistake because it seemed unnatural being there. I think it took about three weeks before I stopped reaching to the right for the ball. Now I'm wondering if I should go back to a right ball on my next project. I'm pretty slow at learning new things.
My initial search for this forum was driven by my ergonomic needs. I can assure you, if my tray wasn't the best, most comfortable solution for my needs, it would be kindling for my next campfire. Form should always follow function.
Thanks for the response. I almost always enjoy your insightful, albeit pointed comments.