I think the term Grid Origin means something different to me than to TC.
The grid, to me, is rather like a sheet of 2D graph paper; its origin is where the two axes meet. That point is 0,0 on the grid.
As far as I can see, when TC sets the grid origin to a new point, it simply aligns a grid intersection to that point. Apart from the way it was defined, what makes that particular intersection special? What does 0,0 mean on that new grid?
It seems to me that a better term for that particular TC function would be Grid Align.
TC21.2 x64 Plat, Bld59
TC16.2 Plat, Bld54.0