Yeah, the clicking doesn’t really help alert you, other than just the fact you will know nothing is left in there.
It alerts you when you get to real zero. I tracked this by noting when it displayed a number like 8 or so, still above the “low” warning. And then I kept track of the bolus amounts until it got below what should have been zero. And it kept clicking and even recorded those amounts as delivered. Generally about 5 units more than what you think is left.
But when it gets to real zero, there is no question about it. You will be notified! Alarm and a deactivated pod. You won’t miss it, don’t worry!