Of course, you can turn off the checkbox AutoSize since you always have the same font size. Delphi, BTW, does not have this property at all and thus works always with AutoSize off.
Just tested: when Checkbox.AutoSize is false, and Checkbox.Font.Size = (some non-zero value), then the checkbox bounds and its font do not change at all when the ease-of-access setting is modified.
Nevertheless, the dependence of the auto-sized TCheckbox.Height with non-zero Font.Size on ease-of-access setting is in error and should be addressed since under these conditions nothing changes in the checkbox with ease-of-access; it looks as if the checkbox uses the default font (Font.Size=0) as reference.