I guess the scenario that is the problem is
- red have PK in a kickable location, but you play advantage as they are attacking
- red attack and gain some ground
- blue commit a second PK offence, in a less kickable location, but now we are close to the tryline so you continue to play advantage as a try seem likely
- red drop the ball.
So now you are going to go back to the PK -- the first offence is best for three points, the second offence, closer to the tryline is a worse kick, but a better chance of a try..
It's not a scenario that will come up very often.
- red have PK in a kickable location, but you play advantage as they are attacking
- red attack and gain some ground
- blue commit a second PK offence, in a less kickable location, but now we are close to the tryline so you continue to play advantage as a try seem likely
- red drop the ball.
So now you are going to go back to the PK -- the first offence is best for three points, the second offence, closer to the tryline is a worse kick, but a better chance of a try..
It's not a scenario that will come up very often.