I wanted to help you with the forgetful operator part. We have replaced our (2) 2250's with two IP computer consoles with software called T-Metrics. We are a Hospital so we have to call emergency codes. Even with a fancy IP Console, our PBX operators manage to have issues locking up the paging trunk by pressing the key and deciding they were not ready and pressing it again or other various issues. We have other areas around the PBX that can take over by using an access code and choose a zone to page like 5900 5901 5902 etc. During this time it would override the operator from being able to page until the trunk free. But the other staff would also have frequent issues and get it locked up. It would be off line for way too long esp with the possibility of a major code like fire. So to resolve this and in your case, forgetting it is open and keep them from saying personal things to the whole organization, we changed the time out to the minimum of 30 seconds. We had them practice their most lengthy pages and they were 99.9 percent under 30 seconds. If there were any lock ups or they forgot to turn it off after a 20 second page, it will drop them after 10 more seconds and reset the page for the next time. We have been running like this for at least 5 to 6 years and we have had no issues. Once or twice a year, we get an operator that talks too long about a car with its headlights on and they get cut off, but the page comes back quickly for the next page. We have never had an issue not being able to page a code in a reasonable amount of time. You may find this works for your system. Very creative by the way!
Thanks!