I'm playing with the idea of maybe compiling a custom kernel at some point, but it would mainly be to trim out stuff i don't need to speed up compile time (i'm using gnu guix, and a few months ago the nonguix substitute servers were down for multiple weeks, causing me to have to compile the kernel myself everytime it got updated). I have a 5800X3D as well and it doesn't take too long, about half an hour i think, but i still think it's annoying if you have to do it regularly. On my laptop it takes like 1.5 hours lol. I'm not sure if it's worth bothering with though, cause i'm also in the process of creating a guix config for my server and then setting up the server so that i can offload builds to it for my other systems (it uses a 3900x).
Btw for how long have you had your 5800X3D? I think i've had it since 2021 or something like that, but i think the silicon is starting to degrade a little, cause this whole time i've also been running it with negative 30 offset, but i've been experiencing hard reboots these past months with errors in the logs indicating cpu-related errors. I've put the offset back on auto and it seems to be working fine so far, so i think it just might need a little more power to be stable.