I am neither a member of the edge diffraction brigade, nor a self-appointed expert on this subject. But there is evidence that rounded over (¾") cabinet edges make for slightly better measurements than cabinets without round overs. Note the peaks at 4 kHz and the dip at 7 kHz.
A Tale of Two Cabinets
Dennis Murphy does not claim that rounded over cabinet edges make big audible difference – only that it can be measured. If rounded over edges are easily done, why not do it?