Good morning, @Dru_Nasty.
QuickBooks Online is designed to use the most recent memo across all invoices. I understand and fully agree that having the option to use the custom message you enter in a new custom style should only be available for that style. With that said, I wanted to let you know I've submitted a Feedback request to our Product Development Team.
Our developers review each request and consider them all for future updates. Any time you'd like to submit new suggestions to our developers, you can do so by using the link I've included below.
Please let me know if you have additional questions or concerns or if there is anything else I could assist you with. Take care!
