Just because someone has an IT staff doesn't necessarily mean that staff really has the expertise to set up a bespoke surveillance system properly. Nor does it really make it a good idea to do so. Nor is it even a good use of time when packaged systems can fulfill most requirements with less integration risk.
The software running on an NVR is only one small part of a surveillance system. I'd be much more worried about the choice IP cameras themselves, which are notoriously problematic. And if you look at the cameras which are well regarded and high quality -- typically those vendors have their own NVR solutions which are also well regarded and already tested to work well with their cameras.
> I am leery of expensive turn-key commercial solutions as they lead to proprietary solutions that school IT won't understand
If IT can't adequately evaluate and choose a turn-key solution, I doubt their ability to piece together their own system.
> If there are better options than Zoneminder please do share the tutorial videos with others here so they have greater options. I am old and clunky so ZM works for me. Some may even say old and clunky can mean reliable and low maintenance.
The last time I tried Zoneminder, the problem I had was that the detection algorithms were so bad that I found them useless. The cameras I had were all outdoors and their algorithm struggled to strike a balance between detecting legitimate motion and not falsely triggering when lighting conditions changed. I tried some other projects that had better algorithms for filtering out changes in exposure and lighting (I forget which ones), but there's also some now that have AI object detection. But ultimately I've migrated away because commercial options got better, cheaper, and more feature filled.
If I picked a new system today I'd probably try something like: https://www.ui.com/us/en/camera-security I don't have any personal experience with it but the value looks incredible.