I'm not going to lie to you, using a premade "bin" type kernel is pretty lame on Gentoo yeah.

Dude it's not had just put the sources in accept.package.keywords

=sys-kernel/gentoo-sources-6.0 ~amd64

Then switch to the sources

eselect kernel list
eselect kernel set # (kernel number eg "2")

Go to it "cd /usr/src/linux"

Then I would start with "make localmodconfig" then "make menuconfig" and just go through it. It seems alot at first but it's easy after.

You have a bootable kernel with the bin. So if you compile a broken kernel boot back into the bin kernel. Tweak the config. Rebuild, reboot. Rinse and repeat until you have a clean custom kernel. Here is my kernel config for ryzen 2700 and Rx 590 for example https://github.com/mrturcot/Gentoo-Stuff/tree/master/filthy-kernel