Hi Chris,
Thanks for your feedback. This is very much based on the existing integration that was built by Dropbox and does not unfortunately sit with our development team.
If the suggestion does receive a number of votes we can certainly look at liaising with dropbox to do a shared development and improve such a feature.
I agree with this also - more than 80% of my invoices go to "Use Once" customers so having the structure "Customers" forlder then Invoices inside the folder adds multiple files for a simple invoice. whereas I would go for invoices under the Kashflow folder