[cthulha]

I'd politely disagree with the assumptions underlying the question.

Changing the physical proportions is a very big deal when you look at the long term impact on the development and app ecosystem.

iOS developers can test their design on the SE, the Plus and the regular size and it will cover over 4 years of phones in the hands of users.

And for what? Have people's hands changed shape or size? Once you've reached something that makes your customer base happy, you would want to have a new design that is substantially better. Novelty isn't a better selling point than knowing you'll be happy with what you get.

There's an old Wired article on the making of the iPod, where they reveal that they made over 100 prototypes, down to weights internally to check the balance and feel of the device. It's likely that there are thousands of iPhone prototypes they have tested out, and the models we have are the survivors of a much larger and longer process than is publically visible.

[rmetzler]

I agree. I'm 193cm (6'4") and have large hands. I still like the iPhone SE much more than any bigger screen.