Yep, I use it all the time. I have mapped zoom in/out to my hatswitch on the stick.

I tested once, sitting in my aircraft on the field with a siren set to go off when the enemy was within 4,5km distance. I knew where the enemy was coming from, so I looked there with min FOV. I could see the enemy aircraft well before the siren went off. Zooming back to normal I couldn't see them. You don't need to zoom in all the way btw, zoom in a little and you will see them up to 4 or 5km already.