"any scenario" opens the door to a lot. Have not seen it done, but was once on a conferance call when some one chimed in that they had 6 legends networked together. Very, very much in the "this is not supported" chapter.
The logic is that you could have 2 Magix systems in the same wiring closet using UDP and centralized voicemail. Each could have 2 T's plus the one between. This seems dangerous to me and creates the opportunity for a LOT of variables, troubleshooting, and Admin nightmares.
If it's my job to administer these systems I would upgrade and go definity.