For CUCM you could do this with Media Resource groups and devices, but being this is CME, it's a global command that issues the conferencing resources for all devices connected to that particular CME. If it is a global command, then there is no way or saying "this group of phones can use xcode and this group can not"
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...