I think it would be handy to have a check box under all devices - to enable pin code request.
I have seen the same in other providers - so this isnt much of an ask - and definitely possible…
For me it would be handy since I have my house shared… but I also have cameras in here, which I might not want everyone to see… plus I have a eachen device controlling my main gate - and I have a sonoff SV controlling a striker lock to my front door… I would be happy if those devices were secured.
and following the same logic - there could be countless things that I might not want just anyone with app access, and share to my house, to be able to control.