Originally Posted by sfosuw

Your experience demonstrated that your non-GE passport is not allowed to be used at a GE kiosk despite your belief that it could (perhaps you were misinformed by somebody?). The point of Trusted Traveler Program is to alleviate the work of the officer by bypassing the officer interview on each and every entry into the country, If you are required to see an officer every single time you're using GE then that defeated the purpose of having GE in the first place and frankly that 10 seconds may seem quick to you, but in reality you're slowing down the traffic queuing behind you who have been granted passage. Using B1/B2 visa in lieu of ESTA is totally your choice, there is no legal requirement to use either or. Some people find it necessary to use B1/B2 because they travel on private aircraft and not commercial. But if you try using your GE approved passport with ESTA, you will not be instructed to see an officer at all.

And to stay on topic, can you use a Non-GE passport at the GE queue?
It seems that you have been correctly informed by some officers that you cannot and in other instances you were just waved through. Those who waved you through is either 1) trying to keep the traffic moving or 2) cannot be bothered or too lazy to bring up your profile to check what document you should be using or a combination of both. It really is a gamble for you as you now opened up an opportunity for CBP to revoke your membership by using a non-GE document at the GE queue.