Refresh takes almost an hour

Hi, everyone!  I'm looking for some advice.  I am trying to create a Power BI Report that uses a few sources:  Great Plains (Accounting software), Business Central and also Dataflows (that pull from Business Central but also from a Cat2 Database).  The refresh takes almost an hour.  What is the best way to decrease this time (if there is a best way?)

Thanks for any help!  One idea someone told me about was to set up an incremental refresh on the Dataflows? (ie - only pull in the new data and make the historical static?)