Again: There is nothing you can do to change the identity of a USB device, unless the firmware implements some trigger. This is done to switch modems from storage mode to modem mode(s), but that's a one-way thing. There is no way to switch back. Nothing any application does can change that.
The switch back to storage mode from modem mode must be firmware initiated.
I obviously cannot check your current measurements, but constant current in modem mode is unlikely. A modem will have very spiky power requirements. The current in storage mode is surprisingly high on the other hand. Makes you wonder how they can burn all that just to run the USB controller, with no USB data transmission and no radio. I wonder if that instrument can possibly show correct values? Maybe it's averaging the current over a long period?
Many moons ago, I used to have a tp703n which has gpio usb controlled. I also have a usb control mains power strip and the main router is connected to this. I have the tp703n connected via main router lan. The tp703n pings the internet and do a gpio reset if internet cannot be reached. Maybe you can do something similar and also scp the config back on at the same time.
I doubt it is averaging over more than two seconds. When I switch to the bar graph, it is build anew and the "worms" creep over the display without major wiggling.
The device has also a WLAN access point, and I think that is what is burning most of the power. The current is suspiciously close to 500mA, so it believe it is possible that the Netgear WNDR4300 or the hub is limiting the current. I plain forgot that I bought a spare Netgear R6220. Checking ... Nope, it's also only got a USB 2.0 port.
The Huawei device page specs the power requirements at < 3.5W, so we may indeed have a power problem.
I propose we put this on hold until I have a USB 3.1 hub (I found out it 3.0 hubs aren't much cheaper, so I'll got for the fastest you can get. As usual, hub's for 3.2 are slow to appear.)
And we switch to the thread I had started for this (USB modprobe problems in 21.02.0-rc3). I'll ping you when I have a new test.
As suggested by others you can use an Android Phone tethered via USB as a WAN with wireguard on the AP.
Alternatively, you could run Wireguard on the Android phone with USB tethering to the router as the WAN.
I use this as a backup WAN on a TPLink Archer C7 V5
I've found a tethered Android phone to provide a really stable LTE connection.
That way you don't have to deal with connectivity issues I've personally seen with modems/modem drivers on Linux.