Maximum I've ever successfully run was 150 simultaneously. This was done using ADB over Wifi. I would like to eventually run 300, but IIRC the USB host limitation is 127. The most difficult part is just keeping everything organized.
The program works with both wifi and regular USB adb devices. But it's going to require some modification if you're using adb over USB and ADB over Wifi devices at the same time
The hub in the video is an eyeboot 49 port hub. Network wise I'm using a pfsense router and 3 Ubiquiti enterprise APs