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.
Well, I can still boot my system without an initram (although that isn't just due to the kernel config)—does that count?
Other than that, custom kernels free up a small amount of disk space that would otherwise be taken up by modules for driving things like CANbus, and taught me a whole lot about the existence of hardware and protocols that I will never use.