You have assumed, because you did everything you could think of, and which anyone has said needed to be done , that those parts are not causing it... but something is missing from the equation... and I don't think those items should be ruled out until you can see them NOT vibrating at the same time you can feel the vibration in the car...very small things can either cause, or several small things can add up to something like this...
When people around me lose things... and I start looking all over... they often say ' it is not there I already looked".... but having found many things ' there'.... I ask them if they know where the item is... and when they admit they don't... then I keep looking all over...and I find the stuff....
Why don't you go to that dyno place, put a camera under it and get the vibration going... ?