Thanks for joining in this conversation, @Laura Baker. 

At the moment, you can only enter the text manually in the Message on the invoice box as it will be the same across all templates. 

As a workaround, you'll want to create an invoice template outside QuickBooks. Then, import your designed custom form styles. Here's an article that will surely guide you throughout the process: Import custom form styles for invoices or estimates.

I can see how great this feature can be for you and your business. Your feedback and suggestions are highly appreciated to enhance our product. Keep posted in our QuickBooks Blog for feature updates. 

If you have additional concerns, feel free to message again. We're always here to help.