Ability to fully replace entire Dataflow M code (overwrite) without creating a new Dataflow, and without having to go into each entity/query one by one. This could be done via import of .json, IF imp...
As a workaround, you can use Marcus Wegeners Publish2Dataflows-tool, that exports all queries from PBI Desktop into a dataflow. There is an option that allows you to overwrite an existing dataflow: https://github.com/MarcusWegener/Export2Dataflow/blob/main/publish2dataflow.pbitool.json
