Two options for the x-axis were explored. The first option was with the 2040 aluminum extrusion upright (40 mm dimension vertical). The second option was to lay the extrusion on its side (40 mm dimension horizontal). In theory, either should work. Practical matters usually are the difference-maker.
In this case, the cable chains and the connections between the x-axis and y-axis starting driving the design. Placing the x-axis extrusion horizontal simplified things. The corner brackets used in the x-axis to y-axis connection were no longer required. The x-axis cable chain could ride on top of the back of the x-axis extrusion, eliminating the need for extra support brackets. And the same bracket used to mount the x-axis motor could also work to mount both x and y-axis cable chains.