I think they have put this quite clear via the pinned announcement, as my acknowledge, eWeLink play the role of IoT solution provider for lots of OEM/ODM partners, SONOFF happens has the same shareholder which is “iTEAD” as eWeLink has, so they work closer than other manufactures relatively, i thinks that’s why SONOFF guys like @Daniel_Zhan have a staff level account in this forum.
For me, i don’t give a shit who is in charge of firmware developing, like it hardly to tell who is the keyrole for Ring devices, Ring or Alexa? especially Ring have become a Amazon owner company years ago.
What i’m care is the quality and stability of their devices and services, and whether my requests are noticed and been put considerable or been developed as a feature, i don’t have time to disentangel the relationship of those companies.