Create a connector directly to the instance of analysis services running under Power BI/Excel
When you are running Power BI or Excel with a data model, there is an instance of Analysis Services running on your machine. You can connect to this using the standard Analysis Services connector, but figuring our the port number on localhost to connect to is hard, and it changes every time you run it, so you can not just refresh this connection. Create a custom connector that will always reliably connect to this instance.
1)I want to incrementally add data to my model vs refresh it entirely.
2)I want to analyse differences between what was loaded from the original data source the last time it was refreshed, to current data. For example, I use this technique to look at changes to peoples departments/titles in Active Directory when analyzing AD group memberships to see of a role change should impact their access rights.