As an ASC tech, we don't care... LOL
I encourage users to take FULL advantage of their devices. Hardware failures are obviously hardware, rooting does not come into play what so ever (ie: white screen). Software and radio related issues is where you have a problem. It's hard enough trouble shooting a device with stock software, let alone custom ROM's. I simply tell customers I will have to return the phone to stock in order to rule out any user initiated errors.