Save System for a Destroyed Actor, or something.

Right now my save system goes like this:

1- Walk in box collider to change ‘Objective Text 2’ to ‘Objective Text 3’.

2- Box Colliders get destroyed to prevent going backwards to ‘Objective Text 1’ or ‘Objective Text 2’.

3- Re-join game to automatically load the ‘Objective Text 3’ you left off on

4- Walk in ‘Objective Text 2’ box collider that was destroyed from last session, restarting progress.

I need a system that will allow the box colliders to recognize if it’s an old objective or if it was destroyed.