When the air starts to suck back into the tire, then stop.
Really, it's going to depend on what you're doing. In the snow, you could and probably would want to take them down to inhale. Especially with bead locks.
In the rocks, you just have to find what works for you, your rig and you're driving style.
Boggers have pretty stiff side walls and yotas are generally pretty light so you usually don't get a huge amount of sidewall flex until you're down pretty far and with bead locks you don't have to worry about losing a bead.
good luck