Yes two things;
With the board there is a tendancy to try and lay the clubshaft on the plane. this creates/encourages a sweep release and can screw up rhythm.
the soft board shows sweet spot plane. because at release and swivel the hossel goes below plane and puts a little dent in the board.
The Bear
This may be a leading question......but if the court will allow it......
When you adjust the Plane Angle to a lower plane , an Elbow Plane say.....while keeping the shaft on plane from Impact to Follow Through and executing Angled Hinging with its associated Clubhead Travel or even Horizontal Hinging maybe too....Does it feel like you are "swinging left" so to speak?
(Im waiting for an "Objection" from someone but I think they're all on other sites maybe)