My DIs are on Herbies gliders right now so this was so easy to try. Strange looking and I must close my eyes to make an unbiased comparison. Ha! Here is what I heard, but will give it more time.
A little hollow in the center and one other noticeable change I think is coming through with this placement. This speaker’s slight achilles heal, at least in my opinion, it it’s slightly forced upper mids. No speaker is perfect folks, but this is certainly a sonic signature I have found with this design. By toeing out this tendency is tamed and smoothed out a tad. That is why some will like it in my opinion. I would think lively/hot rooms and/or fresh out of the box DI speakers would certainly lend themselves to this placement option. It is certainly a reasonable placement option that sounds very smooth.
My particular set of DIs and room finds toeing out to sound a tad hollow between the speakers and ever so slightly out of phase. Both of these are slight. The upper mids are attenuated and smoothed around the edges in my room. I accomplish the pushing back of the upper mids using Roon’s DSP so toeing out is really not needed.
Others should try this if you have ever found the upper mids a little forward or a tad pushed. Nice option.