Holy necro-bump! Anyways, Del, from my experience on the CH quadrant throttle, I don't think it would be very convenient to use those switches left and right of the levers. IMO, if you could put 4 or 8-way hats on the BACK side of the throttle levers, IMO that would be most comfortable.
I usually end up resting my fingers on the lever balls rather than the palm of my hand. The way it sits, I can adust multiple levers easily and independently. However, I can't ready access the buttons on the base of the unit (and I doubt I'd be able to use the ones pictured that you made without seriously readjusting my grip). However, I could keep my fingers on the levers AND use the switches if they were on the backside of the lever, where my fingers naturally rest.
Just a thought in regards to custom layouts. I don't know if it's possible or not.