I have it intergated with an on prem SQL server, no issues. When a new client is added to the SQL database a flow triggers, that creates Sharepoint folders with the clients info, also creates a planner tasks list for the intake process.
I also have a flow that brings the Planner tasks back into SQL so that I can dyanically create links to the Planner tasks list in the SQL database frontend.
I also have a flow that brings the Planner tasks back into SQL so that I can dyanically create links to the Planner tasks list in the SQL database frontend.