Please find the improvements that have been released in the latest update below:
Better handling of invoices without any lines. Quick Books Online doesn't allow invoices with no lines, and they are always $0 invoices. Instead of presenting them as an error to the user (requiring the user to manually remove them in Manage if they don't want to see an error every run), we automatically mark them as batched and explain to the user in the task log "Invoice has no lines - not sent to QuickBooks".
Use the Product ID in the GL Mapping for Deferred Revenue lines (IE: Down Payments). If no Product ID is specified then we'll default to "Down Payment".