Re: Intercepting the Registration/Ping message in the Custom handler.
Welcome to the community and thanks for posting! I know this tool is new to everyone, but for these kinds of questions, you will get better visibility by posting them to our tech forum. When you first log in, you will see a link as one of the four graphics right in the center. Myself and many others subscribe to the tech forum and will see questions when posted there.
Unfortunately, I can't answer this particular question for you but wanted to leave this tip so you might re-post in that section. You can also use the "@" symbol to ask people to join your conversation like, it might be possible that Randy Thompson can provide some details and maybe the Administrator could move this to the tech forums.