Thanks for the idea. This feature has been evaluated by us and we will not implement at this time.
The use case we perceive from the ideas description and the comment involves testing adjustments in a workbook in an ad hoc way and is therefore a designer feature instead of an end user feature. We already provide a user preview from within designer for this purpose.
as of today, when you make a change to a report, the report has to be closed, and opened again. A button that reopens the report would be helpful and time-sparing