There needs to be an app wallet where you transfer BTC already cleared and ready to spend.
A pre-approved wallet would not need any waiting time.
A pre-approved wallet would not need any waiting time.
But this would require knowledge of future transactions that haven't happened yet. Unless of course they have already happened, in which case, they were verified as having occurred at some point in the past, and you don't now need to do anything - you've already paid. However, fundamentally, for a transaction to ever occur there must, at some point, exist a time before it has happened and time after it has been verified to have happened, otherwise it has yet to occur.