In the Queries & Connections pane, show the latest refresh duration of each Power Query query
The latest refresh duration can be stated beside the "# rows loaded."/"Connection only." statement, right-aligned, perhaps in the format "3 min 14 sec". The refresh durations do not even have to be saved in the file. For now, they can be kept for only as long as the file remains open.
The refresh durations in Queries & Connections will avoid the need to manually time each query or use a macro to refresh the queries one by one and record the durations. The durations will make it easier to identify which queries need the most optimization.