Since iOS 9 it is possible to set a picker's height and we support that in Titanium 5.1.0.
However, on iOS 8 the layout seems to use the set height, resulting in the standard-height picker to overflow. See screenshots.
On iOS 8 we should use the standard-height to do the layout. This should also be reflected when you get the height via the size and rect properties.
Found by Eric Wieber and demonstrated in the Ti 5.1.0 sample app