Hello there, gwmtreas.
I got your concern about API successfully setting the income account for each sales receipt but failing to set the class. This information helps the API support team in diagnosing and resolving the issue.
Thus, I'll direct you to the appropriate team. We have a separate forum called Intuit Developers, where you can find engineers who can share suggestions for API concerns and developments. I recommend posting on this website to help you further with app integrations. Check out this link: Intuit Developers Community.
Let us know if you still have more questions about collaborating your app with QuickBooks. We'll be around to help you anytime.
