Hi axiomoholic,
I don't recall if you sent me the private email with the same question, but I essentially said that it's not a great idea for several reasons. The in-cabinet M60s are not measured or designed to be used in that configuration, nor are the double-blind listening tests done with the speakers inverted so it's anyone's guess as to just how the tonal balance and soundstage will be affected if the speakers are inverted.
Also, the dispersion of the drivers and the tweeter in the M60 is sufficiently good that the tonal balance and soundstage should remain reasonably consistent even if the tweeters are 5 feet above your ear level when you're seated. Keep in mind that about 50% of the sound arriving at your ears is made up of early and later reflections from the room, with the other 50% representing the direct sound from the speakers. This combination helps keep the tonal balance and soundstage consistent over a reasonably broad angle.
The amount the baffle protrudes is carefully adjusted in the design and the crossover to accommodate a fixed distance from the adjacent wall boundary.
Regards,
Alan
