To the best of my knowledge, the wait command only delays affects movement commands. It doesn't delay firing commands, facing commands, or smoke commands.
So 'face + smoke + 30sec wait' will change facing first, then pop smoke, as soon as the squad is finished changing facing. Meanwhile, the timer ticks down. In total, they will wait 30 seconds, then move to next waypoint, if they have one, no matter if they managed to throw the smoke grenade or not.