Hi Sonoff product managers
You have a link to a partner with this product…
TOMZN EWelink WiFi Smart ATS Dual Power Automatic Transfer Selector Switch, Uninterrupted Generator Timer, DIN
Are you aware that if the product goes to the Source B configuration then the wifi module is no longer powered meaning it is not controllable by EWeLink. This reflects badly on EWeLink/sonoff and I suggest you either get that fixed or move on to a different like the Geya product that Tuya has partnered. OR even better get an EWeLink branded product made for you and get creative with EWeLink on features. Speaking of which, what EWeLink functionality is available with the TOMZN product?
Cheers
Michael