Question regarding the potential performance improvement for turning off 'Allow data preview to down

I have a question regarding the potential performance improvement for turning off 'Allow data preview to download preview in the background' and also turning off 'Auto Date/Time'. I have a report that takes about 30 minutes to refresh when scheduled daily, there are multiple datasets/queries within the report with numerous date fields in the report and a few million rows returned between all of the datasets. There is a lot of talk of turning off the mentioned options but when I test there is no difference in time when published. Is the download preview option only effective at reducing the time to refresh within the desktop application itself and in reality it has no impact on a scheduled refresh? I believe my main issue is that Power BI is kicking off running each query multiple times as i can see them running when i check. Any ideas whhy is Power BI running the same queries more than once based on experience?