Friendly invitation endings for sign-up links

Instead of a random code can we have an option to add “friendly or vanity” endings for invitation URLs for both regular user and premium signup links; e.g. https://example.community.co.uk/free or https://example.community.co.uk/premium instead of https://example.community.co.uk/4d6tg7 or https://example.community.co.uk/e4n7tc