If the assistant delays flag due to a goal scoring opportunity. Shot comes in, goalkeeper saves it and goes for a corner, will the flag go up or not?
What's the maximum delay between an offside offence and the flag going up?
Part 1) Assuming that the player in an offside position committed an offside offense then yes the flag would go up after the GK saves the shot.
Part 2) There's nothing concrete. It should almost never been more than two or three seconds. In many ways it's like playing advantage and then bringing it back.