You could use the additional radio in other products as dedicated radio for WISP mode. Having a dedicated wifi radio benefits ranges and speed, because uplink network and own network can be on different bands/channels. That way the networks jam each other less and more airtime is available on both.
A well working wifi dongle could therefore be a nice addition to not only the MV1000.
Using usb wifi dongle is sadly not really plug and play in OpenWRT. A well integrated wifi-dongle could work wonders! Finding one the work really well with OpenWRT is also not easy, so having one would be a really nice. (Hopefully a dongle which performs like my Netgear WNDA3200 or better!)
When looking for wifi-dongles, the chipset is really important. OpenWRT needs to have drivers for them to work! Carefully select your dongle based on this fact ONLY! You might need to install some additional packages to make the dongle work as well.
In my case a Netgear WNDA3200 works pretty well for me. It requires the packages related to ath9k_htc to be installed and it does not always initialize properly on reboots, because either usbmode does not change the mode of this dongle or the wifi-driver does not pick it up.
For those playing with dongles. “lsusb”, “usbreset”, “usbmode” and “wifi” are tools you likely need.
“lsusb” will show the attached usb devices.
“usbreset” will allow you to reset usb, so devices have to reconnect.
“usbmode” will trigger dongle, which first present themselves as usb-drive with drivers, to go into wifi-mode.
“wifi” is needed to restart with wifi part of the device, so it will be seeing a newly connected radio.
“wifi config” generates the config you need to add the new wifi-dongle into /etc/config/wireless.
In hotplug those commands can be programmed, so the firmware does them when the usb wifi dongle is connected.