The 20S and SMH10 are designed completely different and the main unit of the 20S cannot fit on the clamp kit of the SMH10 and vice versa. However, the 20S has a earbud jack built into the clamp kit so you will be able to plug in your custom ear molds. There is a not a way to permanently disable the music sharing on a headset. The music sharing feature requires you either be in intercom mode and hold down the Jog Dial for 1 second and hear 2 beeps or start playing music on a paired device (like a phone) beforehand then tap the Jog Dial to go into intercom mode then hold down the Jog Dial for 1 second and hear 2 beeps. Since you don't want to activate the music sharing feature then you will only need to tap the Jog Dial once to open or close the intercom channel. Please update the firmware on your headsets (if you haven't already) then perform a "Factory Reset" on your headsets, pair your Bluetooth devices back to the headsets, and intercom pair the two headsets once again to see if the music is still skipping.