We have five pieces of the plate which, upon personal close inspection, have an axis across their 9″ surface which is shorter than specification, and broader. These are both good mistakes for the step#1 stone, and in exchange, they cannot be use the long way.
I am going to keep one and I boxed up the rest. I didn’t measure them critically vs one another before packing them up tight, so I don’t know which one is ‘best’ by specified observe variance.
It is only for facing the 9″ axis and each piece due its warp will vary in some manner for the two effective diameters, but in all five cases the primary diameter will be notably shorter than the specified 2m, and the diameter going across the stone even wider than 25′!
Dedicate a stone to this shape and off you go.