X10 does not like wireless intercoms that use PLC for transmission either.
Sorry the following epistle doesn't answer your question but is my un-requested $0.02
I had older XPCR that would lock up for no apparent reason. I had to disconnect power to get it to wake back up. This problem was not unique to my unit, and it left me with a bad taste for the Leviton/X10 repeater.
Apparently you have not identified any problems with yours, so good luck.
I have owned Leviton/X10, SmartHome, and ACT brand amp/coupler and find the ACT units (I have owned two different models) problem free and superior in operation (DIMS are handled correctly, no lock-ups, fire storms, etc). Unfortunately they tend to be pricey.
Having said that, here is my second $0.02.
Buy an XTBII and dump your XPCR. Volp's unit is rock solid, and I would not be concerned about it not being certified or UL. A lot of folks on this forum have Volp's XTB products, and I have yet to read one bad word about them. It is all accolades. Shucks, if you are truly worried, put the XTBII on dedicated breakers and mount the XTBII in a metal electrical box for fire proofing.
Disclaimer follows: Nope, Jeff and I ain't relatives, nor do I owe him money, or even know him. He just makes good stuff. If my ACT CR234 dies, I will be sending money to Jeff.
Someone owes me $0.04