Thanks for going forward on this.
While I left it alone for lack of info when other possibilities existed.
I just wanted to note that there are plenty of ways to interface I/O to our servers with some simple shell scripts and/or dialplan entries.
I wrote a few for example that are very inexpensive to do.
More Site Control Devices TTL232 and 16 relays PC or Pi.
I would say for those more timid about scripting to get your feet wet as it not that hard at all.
You learn things one issue at a time.
You may be surprised what you can do once you get those wheels turning.
Create something you need and share it with the rest.