Following up on the ABTC and Global Entry issues on a second passport, it shouldn't work with ABTC since the passport details on the card are supposed to match what is in the passport that is presented.

But I checked Global Entry and there is space for three passports and one of mine was a second passport that I used to have so it appears you can have a second passport added and use Global Entry. Assume you have to go into the Global Entry office to have them enter the second passport information.