I would be happy to give it a try. Would your example reflash
the sonoff device to turn it into a native web thing? or go through
some other gateway addon? Ideally Sonoff and other commercial Wi-Fi
(or wired) devices that support IP comms would be sold with native
web thing support.
For this test I don’t care if I need to hard code a Wi-Fi ssid
and password into the Sonoff device firmware.
Ultimately though, for commercial devices, it would be nice to
have a universally recognized and broadcast ssid/password that all
native web things default to looking for when they are
unprovisioned. (The ubiquitous “provisioning channel” would be
isolated and all network traffic dead-ended to the AP that is
broadcasting it.) The temp connection would be enough for users to
“find” new IoT/WoT devices and authorize them (or not) to obtain
secure/private network credentials.