In mission editor:
1. Place player as any soldier unit with 3D optics (ACO, ironsights etc)
2. Preview mission. Wait until mission starts. Pause mission.
3. In debug console, execute the following: player setCustomAimCoef 100
4. Resume mission. Raise weapon optics. Wait until the weapon is aimed far off the centre of the screen, then pause.
5. In debug console, execute the following: player setCustomAimCoef 0
6. Resume mission. In optics view, notice weapon is not centred on the screen.
7. Lower optics. Notice crosshairs are huge, and weapon aim is permanently misaligned with crosshairs.