Hey Imac, I've tried this myself, albiet very roughly and quickly. A piece of dense foam about 2"x3"x3" was lying around at work so I cut an M10-width sized notch in it and put it on. It seems to work pretty nicely and definitely spreads things out, although I haven't listened really closely yet for any nastiness caused by reflections. I'm sure with a round disk and a bit of dampening like you said the results would be excellent. The PCM-M10 definitely needs some help in this regard, so go for it!