I think more than true integration, I am really interested in getting the customer and other relevant data from my FM database into QuickBooks so I can start doiing invoicing on March 1.
I am ok for now with updating things back and forth between the two systems manually for now. There are less than 50 customers.
I suppose I can use FM to export appropriately formatted .csv files and import them into QuickBooks Online for now to get started.
Your csv exports can be scripted to save time and reduce the chance of mistakes in setting up the export each time.