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.
I run linux-xanmod-anbox for root support in Waydroid (Android on Linux).
And I configured my kernel to support VFIO (Virtual Function Input Output).
So I can fully pass through one of my GPUs to my Ameliorated Windows KVM,
which I use for both work and gaming.