At the very least, I’ve verified that adding an interface (second USB tethering or WiFi repeater) and load balancing work perfectly if I’ve set it up properly according to the mwan3 default settings.
- difference in transfer volume is due to Metric and other intentional settings and is fine
However, many smartphones on the market have some restrictions to control routings, and it may be difficult for the GL UI to set up everything automatically because it is necessary to consider common troubles due to multi-WAN.
In my case, I’m using non-rooted Android 9 and 10, but I had to be aware of device-specific specifications and limitations on the USB tethering feature.
Moreover, the gateway, DNS server, and address ranges are nearly duplicated, which can be very cumbersome to control routing.
After all, I had to disable all QoS features (including SQM) to eradicate routing errors…