I would disagree with the concept of adding or changing anything to a vendor name.
You never know when the IRS is going to change something that affects the vendors and reporting. Vendors you do not issue a 1099 to now, might need a 1099 in the future, or some other form.
Modify the customer name only.
IMO the simplest is to add a period after the first or last name, hardly anyone notices it when it appears on an invoice or sales receipt or even a report