Yes the CM15A does send X10 power line signals. If you have set in the Tools Tab, Hardware Configuration, Transceived House Code to the ones you want to send. I used specific and picked the House Codes I needed to use. Auto has sometimes been reported as a problem. You can also set it to None. Then no House Code RF commands will be sent. Just used in AHP to to do things like Macros.
There have also been many reports on poor RF reception range and modifications to improve it. Can't say about the latest ones with no Receiver and Transmitter Daughter Boards now all on the main board.