Curious to know the coolest things you achieved by configuring your kernel. I know kernel config can be boring, but I'm hoping someone will have an impressive answer.
For me I have a very lightweight kernel that runs wayland on nvidia without any issues to date.
The secureblue image I use disables numerous kernel modules, and enables many kernel mitigation argument.
The performance impact is minimal, hopefully that means a more secure system? I honestly don't know, nor do I change the default recommended by the developer.