The ability to have first name only on e-mail body templates for invoices.
We actually cannot achieve this as we store a contact name as a single string for a business. If you select "individual" then you get the first name last name option.
Changing this in the database would cause data issues for users who have populated this data. ie what is first name, what is last, is there a middle name, prefix and so on.
For now we will leave "as is" and try to solve another way in the email itself.