Independent Data Source refreshes and ability to have a week day refresh frequency

Currently it is only possible to set up a scheduled data refresh at the report dataset level.
Would it be possible to change this so that each data source can be refreshed to it's own individual schedule?
For the reports I am currently working on not all data sources are updated daily: some are only updated weekly and so do not warrant a daily refresh.
Furthermore, none of my data sources is currently updated at the weekend which makes refreshes over the weekend pointless.
Currently options are limited to all data sources being refreshed Daily or all of them Weekly including weekends. A Week Day option would be also be a welcome addition for example.
Hopefully my suggestion makes sense :)