stop refresh in data preparation phase

Hi Team, Is there any way to stop refresh in each and every step in Power Query. During data preparation, if add any step data refreshes from source for all files merged/appended in that query. We need some feature or button so that once data is downloaded in Power Query, it should not refresh again until we switch on that button. This will enhance the speed in data preparation. Else we have to wait minutes after each is performed. This will help In cases where we cannot see results on small data sets and have to full data even in data preparation phase.