No, we run a fleet with thousands of physicals and hundreds of thousands of virtuals, of course we don't hardcode keys in our SSH configuration. Like presumably every other large fleet operator, we solve this problem with an internal SSH CA.

Further, I haven't "moved on to another argument". Can you answer the question I just asked? If I have an existing internal PKI for my fleet, what security value is a trust relationship with DNSSEC adding? Please try to be specific, because I'm having trouble coming up with any value at all.

We also have thousands of devices accessible over SSH and we maintain our own PKI for this purpose as well. We also use mTLS with a private CA and chain of trust, for what it's worth.

It's a solved problem, basically.