import to direct query

I would like to have a "developer mode" that allows a set number of lines to be imported as "sample data" so that we can see the data and our manipulations, but doesn't take too long to update whenever changes are made.
In this mode, we could clean the data, make all of the calculations and measures, and build the dashboards and reports.
At the end of the "mode" we would be able to either click "import all" to bring in all of the data or "switch to direct query" to connect to the data in that mode, but retain all of the manipulations, measures, calculations, and visuals we made with the "sample data."