peteroznewman
Bbp_participant
The point of maximum deformation is going to be different from the point of maximum strain, which is what you began the discussion with and caused my confusion, but now I see what you want.
How much does the point of maximum deformation move about in the model as the parameters change? I suggest you split the plane into 4 quadrants and reconnect them with the Share button in SpaceClaim so you can get a vertex at the center which will be close to the point of maximum deformation and you can request stress at that node.