Lasso mode doesn't inpaint at full resolution

When using lasso mode and "inpaint at full res", the resolution gets reduced to the base resolution dimension square around the shape. It doesn't maintain the resolution set with the width/height sliders.

So, for example, if I have ratio mode selected, and 768 px as base, and then make a wide selection, the width/height sliders say something like 2171 x 768 px. That is correct, and that is the resolution that I expect the generation to be made at (or perhaps slightly bigger to account for mask expansion, blur, inpaint padding, and offset). But then when it generates the area, the size of the generation is changed to a square, and is generated at only 768 x 768px. Shouldn't it generate the area at the full resolution of 2171 x 768 px (or larger), especially if "inpaint at full res" is checked? And why does it change it to a square?