In many cases, a bass-reflex cabinet can be made of arbitrary shape. The important thing is the volume of the cabinet and the size of the port. However, this really only holds up for boxes that are acoustically small. Larger cabinets can develop pipe behavior and cabinet proportions and driver/port placement then become relevant. The two π tower was designed with computer models that simulate both Helmholtz resonation and pipe mode resonation. The dimensions and driver and port placement were adjusted for best response using these mathematical tools, and then the completed loudspeaker was measured to verify its performance.
If the speaker were smaller, I would say you could probably change dimensions without worrying too much about sonic impact as long as the volume was the same. But in this case, the dimensions and driver and port placement are more important, because they determine how standing waves align themselves inside the box.