I updated to ATV 2.3 from 2.2 w/aTV Flash 3.3.5. Then, I created the USB stick with the ATV 2.3 OSBoot image and the aTV Flash 3.4.2 image. It successfully installed, but under maintenance -> about aTV Flash, it says I’m still running 3.3.5. I’m going to see if everything works. I still have to patch for USB functionality.
Despite the incorrect version number, everything works fine. False alarm.