A one2many fields in a wizard view is empty while the on_change should have filled it

This issue is the result of a chain of action with the good timing so it's a bit difficult to trigger.

So in my custom code I have a O2M that contains two O2M, when opening this view in a wizard the values are populated thanks to an on_change call trigerred from the default values received by the wizard.

In this case, the inner O2Ms do not display the values received from the on_change because the model used to set the values do not have any reference to the fields set. Those model are created when display has been called on the respective widgets which will ultimately fill the model with the fields but since we're not returning the promise at the end of Sao.Screen.new_ there is a scheduling issue between all the asynchronous calls in sao.