Apple has built iPhone Duo 2 prototypes with Face ID, Bloomberg's Mark Gurman reported on Sunday, and engineers are still working to fit it into the outer display. The first Duo unlocks with a fingerprint sensor in the side power button instead. Apple also wants an Action button on the Duo 2, possibly folded into the Camera Control button, and a telephoto camera and a thinner, lighter body are planned for the next couple of models.
The Duo 2, codenamed V78, is expected next fall, so Apple has to settle its hardware about now. Gurman calls it a toss-up whether Face ID makes it in time, though it's Apple's top priority for the next foldable. If the fingerprint button is what kept you off the first Duo, don't count on the 2027 model fixing it.