I was simply correcting the device flow you'd posted. Obviously I have no idea what else is involved in your particular case.
Regardless of how the rest of your setup will…

Trained many a T field tech on the install of them.
Diagram to better show what I mean tomorrow.

Few weeks late on this, but it will be:
lead-in -> central splitter -> mode 3 socket (with alarm connected) -> other phone sockets
There will a separate line run from the…