It would require a major iOS re-write though. Designing for e-ink is a really different paradigm, both statically and in relation to UX interactions. I just returned an onyx boox note because although the hardware was quite nice, the UI was just garbage. I'm sure Apple could do it, but it does't seem very on-brand for them. I'm waiting of a delivery of an RM2, but I'm still not that hopeful that they have solved the problem of reading an A4 academic PDF. Yet another reason to kill off the commercial academic publishing industry — we can get proper epubs of papers!