Hello - I just finished porting ZM Server and ZMEventnotifications to Termux running on a non-rooted Android phone. The purpose was to deploy a surveillance network in a location that only has access to mobile networks and to combine the functions of a mobile hotspot and stand-alone linux computer onto a single device. My network consists of a Samsung S9 with multiple esp32cams running rtsp streams, and is powered by an off-grid solar system. So now I can tunnel into the phone via ngrok and access ZM web pages or receive sms/email notifications when the event server detects specific objects, such as "person".
The distribution is simple to install into Termux as a backed up ubuntu tarball, although it is 2GB. Reinstalling everything from scratch into Termux was somewhat of a pain due to the need to install platform-specific python modules and a number of other random issues that were encountered.
I can think of a number of advantages to running ZM on a mobile device. If the cameras had their own uninterruptible power supply it would be difficult to defeat the surveillance network by cutting the power or internet connection. And of course, you could deploy the system anywhere that has mobile network access and it will run until the phone/camera batteries die. It is a rather inexpensive hardware platform if you were to obtain a cheap used phone.