In my experience, they find it anyway. I've run ssh on non-standard ports for over 20 years, and my auth.log is gets a hundred knocks an hour - and mind you, t

In my experience, they find it anyway. I've run ssh on non-standard ports for over 20 years, and my auth.log is gets a hundred knocks an hour - and mind you, they all return "no key". It's just life, and it will continue to get worse. Secure your server and ignore it.