Well, it's been an interesting and frustrating few months, and I've come to the conclusion that I am wasting my time trying to use the 3EM for any serious purpose. Initially, I had problems with the firmware corrupting the device that meant it ended up with a WiFi password that could not be reset or recovered, even after a factory reset, and the device was replaced.
Once I had that, I was able to set it up, and in theory get it working, and due to the location, I ended up having to get a wifi extender so that the device got a reliable signal from my network, and to avoid having to use the only ethernet connecting cable that runs to my garage, which is normally used to connect to the standby generator control panel, I got a powerline extender device. It works without issues if I am in the garage with my laptop or mobile phone, but for reasons that escape me, the 3EM is not stable, and is lost on a regular basis from the network.
I got this device with the intention of trying to monitor my power usage with a view to installing solar panels, and so far, it's been a complete waste of time and money, in that I cannot get reliable usage information from the 3EM, mainly because the software is so unstable, which results in it being lost from the network pretty much most days.
So, in a nutshell, to anyone that's considering this device as a power monitor, be VERY careful, as it seems that for reasons I cannot get to the bottom of, while the hardware might be reasonably good, the software is still very much not stable, or fit for purpose, as the device does not provide a stable platform for gathering information.
I was considering installing some other Shelly devices, I could use a number of thermostatic radiator valves, and some of the timers for things like gates, and controlling other devices in the home, but the experience with the 3EM has caused a change of plan, I can't afford the time or effort that seems to be required to support these devices, the regular problems with the 3EM mean that I am not going to risk making my problems even worse, I want technology that works, and at the moment, it seems that there is some way to go for Shelly to become a stable supplier, at the moment, there is no way that I can recommend the shelly devices as a viable option for stable operation.
It will be interesting to see if this post survives, I've been involved with computers and on line support for a very long time, and I thought that I'd found a reliable supplier, but it seems that my research didn't go deep enough into the issues. or there is selective editing of posts being performed that means that negative posts about the devices don't survive for long, which results in a distorted picture of how the devices are actually performing.
Pity, but that's life in the sharp end of home computing and automation.