I rarely use them for communication and mostly for music. They sound real tinny with all highs and no lows. If those Schure ear buds are as good as reported, then I think all I would have to do is to put a headphone jack on the headset (which the lady in AZ said she could do very easily) and I should have a good sounding bluetooth stereo headset. I could pair the Cardo to the Garmin or to an aftermarket bluetooth head unit if I ever upgrade. That's my thought process, do you see any holes in it?
The only hole I see is the one in your head

of course only referring to your ear canal. You are getting exactly what those Cardo's are made for and the result is tinny and no base. But, I can plainly hear mine at any speed for voice coms.
Are you referring to using ear buds along with the Cardo speakers for voice? Don't know. I haven't really giving any thought to the ear bud method as that is just one more thing to have to plug unplug.
Whatever I finally end up with my goal is to be able to control the music, especially the volume from the handlebar controls. And getting my "speed compensated volume" to work again would be a real bonus.