Hi David,
I think that the calculator is right, and that on your diagram, the ranges marked 2.31 and 4.62 are right, but that these are each half the intended offset for use in the offset tool. You are measuring from the Profile line to the point of the cutter; you need to go the same distance again to get to the other line that the V-cutter must follow.
Your "Inlay Offset" caption should be to the left of the Profile line and the offset itself should be 4.6188, as shown by the calculator. This is twice the width of the arrows you actually have. Where you do show "Inlay Offset", it should show "Substrate Offset" and the value should be -9.2376. Again, the width of the arrows should be double.
if you look back to my original diagram, the places that you have marked correspond to the boundaries of the zone to be hogged out with a milling cutter, should this be needed ("Inlay Pocket Clearance" and "Substrate Pocket Clearance"). Actually, I made a slight overcut, allowing something for the width of the glue gap, but it is much the same thing.
I wish this stuff was easier to explain. I believe my initial description is correct, but you need to be a lawyer or a computer to follow the description! Sigh!