If you're going about that level of security (and you should be!) - why are you bothering with SSH being open to the public internet to begin with?

This is what's weird to me about this whole argument - people can come up with lots of ways to secure this, yet aren't willing to do one of the things that will provide the most security while also offering a high pass filter in blocking SSH access to the public internet. No log noise, no chance of a zero day hitting it, one key being compromised is no longer enough to result in an access breach.