@david_h 

Hello, sorry to tell you that the KC200 can be managed via the mobile devices now. 

Meanwhile, for the Lenovo Google smart display issue, we have reached out to Google already, it seems that there is something wrong at their end, and they plan to release a new update soon, you can check their official website or contact their tech support for more help.

One camera can be bound to one account only to protect the security and privacy, while multiple devices can use the same account to manage this camera. So it does support multiple logins. 

May it help.