I have installing unified systems for small jobs since 1997 I can also install 2 separate networks like you guys do. what ever works best for my customers is the way to go
here's one from 1998.
https://web.archive.org/web/20011224212417/https://directconnect.bizland.com/images/10baset.jpg

I started doing this in 1997
https://www.contact-directconnect.com/Smart-Jack.jpg

Nordx IBDN/CDT Certified for Whats Comming Next!