I'll throw my hat in the ring...
I helped to facilitate 4 pre-orders, all through IUP (all completed the pre-approval.).
3 iPhone X Silver 64 GB (Verizon) - Nov 10-17
1 iPhone X Space Gray 64GB (Verizon) - Nov 3
The apple store app experience was weird to say the least. It was a trickle effect. I was able to get in first, then another relative, then my wife's phone and finally the last relative. We were all in different locations with the exception of mine and my wife's. It seemed like from the very start, the Silver iPX was in very limited supply. I think I got my actual order in around 3:04am-3:06am(EST). Space gray remained with a Nov 3rd ship date until around 3:15am. Silver was pretty much done out of the gate.
The fifth phone I needed to pre-order was a new IUP order. Apple couldn't reach Verizon's network to verify the account details so I got the whole "cannot reach carrier, we will reserve one for you and email you when we can reach the carrier so you can complete your order." At that time, it was another iPX 64GB Silver, which had slipped to 2-3 weeks.