Hey there AJSteward,
The Workflows feature in QuickBooks Online Advanced, is a dynamic way to automate tasks and send reminders to your customers effortlessly. Once you set the conditions, QuickBooks will send out a reminder. I'd be happy to provide more information, so you can send your customer statements in a timely fashion!
Once you've created the workflow for Recurring Statements, you can choose to show Open Balances (365) days, Balance Forward, Open Items or Transaction statement. In the 'When this happens' section, you choose the Customer Name. However, at this time, there isn't an option to choose 'All', so you will need to select each customer. If this is something you would like to see incorporated moving forward, please don't hesitate to submit a suggestion to our Development Team.
If you have any other questions, feel free to reach back out to us here.