I know this too and the reason is because Parent is read-only.
modViewsUtils - code module:
B4X:
Public Sub MoveB4XView(xView As B4XView, Destination As B4XView)
xView.RemoveViewFromParent
Destination.AddView(xView, xView.Left, xView.Top, xView.Width, xView.Height)
End Sub
B4X:
Public Sub MoveB4XView2(xView As B4XView, Destination As B4XView, Left As Int, Top As Int, Width As Int, Height As Int)
xView.RemoveViewFromParent
Destination.AddView(xView, Left, Top, Width, Height)
End Sub
Private Sub B4XPage_Created (Root1 As B4XView)
Root = Root1
Root.LoadLayout("layTwo")
modViewsUtils.MoveB4XView(B4XPages.MainPage.pnlBottom, Root)
End Sub
If then I need to move pnlBottom to MyPage3 I need to know that it is now in MyPag2.
However, this was more a curiosity than a question or "wish", which came to my mind when replying to an Italian member. If I want to use the same View, even a complex one, I create a Custom View.