We asked for this integration last July when we moved all of our sales from QuickBooks POS to Square and then moved to QuickBooks Online.  There are definitely some areas for improvement on QuickBooks side.  Being able to fully pass inventory data back and forth daily, or even on a push basis,  would be wonderful.  The other thing I have not been able to find where to fix is the Uncategorized Expense integrating to QuickBooks.  We have a Square Capital Loan and the deducts from each card transaction land in Uncategorized Expense.  I have to manually move it to the correct payable account.