Option to assign a default number to individual contacts, if your phone has more than one number. I know you can choose what number to use in the message window, however it's too easy to forget to change it or accidentally hit send without choosing a number. I've accidentally messaged people with a number I didn't want them to have, I have a Galaxy S21 Ultra +, and use an esimm, so I have a second number I use for non personal messages.