invoice email customization

re: QB Desktop Pro 2018

I am searching for the default .oft file used by Outlook when emailing invoices from QB. I already understand how to edit the text via Preferences>Send Forms>...etc. I want to find the .oft file so I can modify the layout of the email message.

My issue is with the generic formatting of the table/cells, blue border, fonts, and the location of the 'View & Pay Invoice' link/button. For starters, when a lot of people see an email with predetermined formatting, they think newsletter or marketing junk, and don't bother to read the content. My concern with the View & Pay Invoice button is that it is buried at the bottom. Often times, my invoice emails are unique for each customer & contain a lot of info. If they get past the generic formatting imposed by QB and read the content, they do not always scroll down to the very bottom to the link, especially when viewing on mobile devices. I simply want to be able to have this at the top and for the content of the email to be clean, simple & consistent with the look of all our email correspondence.

FYI - I have found an .oft file in C:\Users\<username>\AppData\Roaming\Microsoft\Templates\qb.invoice.email.oft. However, when I modify this and re-save the file, it does not take affect when sending a new email from QB.