I have a Unifi Dream router and Unify 8 port switch, also I have several Access Points over about 4 acres and it works very well for my purposes.
I have about 20 Eufy Cameras spread out over the property. A year or so ago I tried to create an IoT network to put all the cameras, and Smart Plugs on. I got the network and the wireless network created by making it a guest network and applied to two rules for allow established and related and to drop anything from the IoT to the default or main network. However I never could get it to let my eufy app see the cameras, so I deleted the networks and went back to having everything on the default.
Over the last couple days I toyed with it again and kept reading and watching Willie’s video on it. Finally this morning I made the network a regular network instead of guest, and clicked isolate. Added the two rules and now it’s working fine, and I can join the IoT network and ping the UDR, so does that mean it’s working as it supposed to? I assume it does but I know too well what assuming does. 
I also added my smart thermostat and GE Profile washer and dryer to the IoT network as well. Was wondering if I should also put the Apple TV 4K in the IoT? I read some about it and a lot of folks leave them and HomePods in the default network so wasn’t sure. Thanks in advance.