I now have a CM-15, TX-6, and TP-7. There are surprisingly few resources about how to use them together and with other gear, so hopefully people can share their tips here.
My tip is that there’s a CM-15 setting in the update utility called USB Charge Mode. If you disable it, you can use your CM-15 as a USB audio client even when the power switch is off. I go into a bit more detail in this video: https://www.youtube.com/watch?v=X_lOFVxp7oc
This way you can use your CM-15 as a USB mic without ever having to turn the power on (and thus not accidentally draining the battery if you forget to turn it off).