Hi @msallin and sorry for the hassle with this.
The default width of the iPhone 5 (or SE) is 282px so the IOS picker should work fine there.
That being said, we definitely need to make the control resizeable so that it can fit the other iPhone sizes. I’ve just given this request a nudge, thanks for the report.
Please let us know if you need anything else, we’ll be here to help!