I agree with angel.
A lambda user, me too, would expect B4XComboBox.SelectedIndex instead of B4XComboBox.GetItem(B4XComboBox.SelectedIndex).
The lambda user is most of the time not aware of the internal 'life' of the CustomView.
It's similar in quite some other CustomViews, like as an example the CustomView.mBase.Left property, the lambda user would expect CustomView.Left.
I know, it's easier for the programmer, but it's more difficult for the users with it's habits.
What about Inheritance !?