I've never been certain how the 2.4 steel frame grille plate affects the diffraction 'problem' as it tightly surrounds the coax with 3 cuts at about 20 degrees, 0 (vertical), and 30 deg. But the steel still presents as an edge, a discontinuity, for the coax wavefront. It is just closer to the coax than the baffle edge when the grilles are off. If you removed the grille cloth off the steel frame, it would more-clearly visibly *appear* to be problematic wrt 90 degree discontinuities closely around the coax.
I'm happy to entertain the soundstaging differences are from something unrelated to the baffle differences, which appear to be such an obvious contributor. I've had my 2.3 coaxes in my 2.4s for extended periods waiting for replacement 2.4 coaxes, but beyond an interesting change of frequency balance, couldn't discern any soundstaging differences...
I'm happy to entertain the soundstaging differences are from something unrelated to the baffle differences, which appear to be such an obvious contributor. I've had my 2.3 coaxes in my 2.4s for extended periods waiting for replacement 2.4 coaxes, but beyond an interesting change of frequency balance, couldn't discern any soundstaging differences...