I recall long ago in this thread when someone asked about smaller device in the future, it was said that nowdays market does not offer screens smaller than 5,5 inch or so. well, after now a low-budget ultra-small phone is released - the Xiaomi Qin 2, we know that small displays are not the problem. so we can bring up that question again: how small the Pro2 / Pro1 compact can theoretically be?