While your use case is valid, it's nowhere near as annoying to have to wait 1 second for a button to enable than it is to call random person from your contacts

While your use case is valid, it's nowhere near as annoying to have to wait 1 second for a button to enable than it is to call random person from your contacts because his name appeared under your fat finger. Maybe there can be a distinction between expected layout change and ad-hoc elements appearing, like notifications, list updates etc. I would probably go too far asking for a setting of "time to enable after layout change"