I posed the question to the speaker manufacturer and they wrote back:
"Hi Nick,
I forwarded your question to our head engineer, and he strongly urges that you not do any of the things recommended on that website. Many of the things recommended on that website will make things worse, some can even cause damage to the audio equipment.
Removing the diffuser from the M6 will make its high frequency dispersion worse. It will make the speaker brighter on axis. It will be different, but not better. This assumes that the customer can remove the diffuser without damaging the dome.
Furthermore, it would void your warranty. It is therefore our strong recommendation that you not modify your T6 in that manner."
I'm glad I asked, thanks all.
"Hi Nick,
I forwarded your question to our head engineer, and he strongly urges that you not do any of the things recommended on that website. Many of the things recommended on that website will make things worse, some can even cause damage to the audio equipment.
Removing the diffuser from the M6 will make its high frequency dispersion worse. It will make the speaker brighter on axis. It will be different, but not better. This assumes that the customer can remove the diffuser without damaging the dome.
Furthermore, it would void your warranty. It is therefore our strong recommendation that you not modify your T6 in that manner."
I'm glad I asked, thanks all.