The tethering is the most reliable thing for me with these routers. I plug my phone in and BAM! Internet.
Now, the only difficulty I have sometimes is the initial pairing - never had an issue beyond that.
Once initial pairing complete, I leave the ‘personal hotspot’ toggle activated all times in the iphone settings.
Bear in mind this does not leave tethering on all the time… only means that your phone is not blocking tethering.
You can long press the wifi and bluetooth buttons in control center to access a quick button to temporarily activate wifi and bluetooth tethering.
You do not need to interact to make usb tethering just work beyond plugging in the phone in my experience.
If you switch the toggle to ‘off’ then I think you have to put your password in to ‘trust this device’ each time before connecting.
If you are using wifi tethering via the button in control center, the name of your network will only appear for a few minutes and will eventually become hidden. If you activate wifi tethering from the toggle in ‘personal hotspot’ settings, the wireless network will stay visible indefinitely (or until you leave that screen).
Hope that helps