In reply to Ahmad Awais.

@mark-k How about posing your question on Stack Exchange and we can work out a solution there for posterity. Short answer is that the WidgetPartial needs to extend its refresh to invoke the fallback method when such a change is detected in the widget's instance data. Or a better solution could be listening for the partial-content-rendered event. Or yet again, it could be better handled on the PHP side by adding a customize_partial_render filter to return false when the instance data perhaps disagrees with the placement context in regards to this aspect. Bottom line is there are a few options available so we can look at which would be best and perhaps establish one as the standard best practice.