Originally Posted by
MeltingAlf
Deadline usually is when they announce "boarding completed" or when it happens (sometimes they don't announce it).
Sometimes it happens a little later when jetbridge is removed and pushback commences, for example when there is ATC delays and whatnot.
In your above cases, the cabin crew definitely should already know the status of the passenger, Diamond, Gold, etc. beforehand and might even have greeted the passenger accordingly during boarding. And if you subsequently use apps to switch FFP or un-identify your CX status, will the cabin crew then treat you as if you are nobody?