Having the right feature on the software is imperative. At the moment, you'll have to uncheck the Billable box manually.
I will send feedback request directly to our engineers regarding this option. They can consider the feature to turn off the billable box when creating from the Sales Order in the next update.
Also, in case you need some related help articles for your future task, please check this page: Accounts Payable workflows in QuickBooks Desktop.
If there's anything else you need, don't hesitate to reach out.