What I've done is just expose those properties via public properties of the form:
Public Property Title As String
Get
Return Me.GradientHeader1.Title
End Get
Set(value As String)
Me.GradientHeader1.Title = value
End Set
End Property
The other option would be to make the gradient header public, using the Modifier property:
Then you could use code like:
MyForm.GradientHeader1.Title = "My Title"
I don't see any way for SF to know how you'd compose your forms to automatically provide this sort of functionality though. Fortunately it's not hard to get working though!