The device has got two switch buttons that could be used to facilitate the wi-fi configuration by using push-button WPS:

• FN: only used to enter the bootloader mode
• Wi-fi: used to clear the wi-fi settings if pressed during the boot, but not using for anything else.

The second one seems more suitable for the purpose and the label already placed. Ideally, there should be a dedicated WPS button to avoid confusion.

So instead of entering the device's captive portal and inserting the SSID and password, the user could simply auto configure by pressing a button on both the device and the wi-fi router.

Use flow:

• with wi-fi not configured, the screen will instruct the user to either log into the captive portal (current method) or press the Wifi button for WPS automated process
• user presses the WPS button on the device
• screen instructs the user to press the WPS button on the router
• with success, inform in the screen and reboot the device

This example seems to have potential, but I didn't analyze it in depth yet.