I just recently got a SmartLabs PLM and I have been toying with the same thing, trying to make my own homebrew macro controller.
My PLM is revision 63 in case it matters.
I have found that I can make my PLM report events from prospective Actors as long as I “force” Responder links for those Actors into its device table, and then enable Monitor Mode. My Actors don’t even have to be Controllers of the PLM for it to get the traffic. (However, all the better if they are, so they can ensure the traffic is acknowledged).
I had a very difficult time getting my EZSrve to force links into its internal PLM even though the commands to do so are documented – they appear unimplemented and non-operational and return an “Invalid XML” message. I tried this, thinking that this would make my broken macros start working. (I was able to get macros working if I did the normal linking sequence between the EZSrve and my light switch).