I have used thingiverse supplied tools for scaling and offset correction and found that the spreadsheet recommends that I need different offset values for X and Y axis.

I am not trying to correct for poorly set x and y axis steps per mm. I have checked physical motion of the axis and it is accurate enough to disregard as a potential cause.

Can we please have the ability to set different x and y axis compensation values in place of the single "XY Size Compensation" variable in the "Advanced" page of the "Print Settings". I would suggest that there is a primary cell and secondary with the secondary defaulting to the same value as the primary in order to not give any back compatibility issues.

I am considering using tools like mesh mixer and blender to try and achieve the same goal, but I believe this is better tackled at the 2D slice level, rather than trying to apply a transformation to the 3D mesh.

Thank you for considering this and the continues development of Slic3r. I look forward to seeing what novel features are in the works!