Restaurants getting too aggressive with verifying pickups

Since last week, have had at least 3-4 restaurants demand (quite aggressively) that I verify the pickup. The issue is that they ask me to do while food is not ready yet. This is where I have a problem. I tell them, yes I will of course confirm it in front of you... As soon as the food is in fact ready. But they have been insistent on me doing it before, which for now I have refused. I tell them I will definitely do it, again when the food is ready, and have had to make up a story that I can't / won't do it until the food is in fact ready because if I verify now, the "delivery timer" begins on me delivering it. It makes no sense for me to verify it while the food is still being prepped. And despite this, I'm still getting dirty looks and grumbling. And in all those 3-4 cases I had to wait several minutes before that food was ready. Yeah hell no I ain't verifying early. F-YOU. I get it you've had food stolen, and am very willing to verify in front of you, but this is going a little too far.