Yeah, I used that example to tinker with this. It basically denies NAT'ing for "interesting" traffic.. or what I was needing between 10.17.12.200/29 and 10.18.12.24/29.. but it was still double NAT at best between the cell phone and the Netgear router.
I'm hoping you're right and it was just the Netgear router.
Never work with Netgear products, but I'm guessing there should be some options you can turn off NAT for interesting traffic. Cellphone feature is however limited, depending your cellphone make, model, operating system, and the apps you are using. I believe cellphone companies always implement NAT and unless you have bargaining power, there is nothing you can do or say to the cellphone company to turn NAT off. What you can do is to use Wifi network sitting outside the router and to have the laptop to use Wifi network to establish IPSec VPN.