I was directed to try the kernel defconfig here https://github.com/sarnold/arm64-multiplatform/tree/v5.16.x/patches, and it seems to have done the trick. Still don’t know what was wrong about my original config, but given the number of differences it’ll take a while to find it.
I would’ve replied sooner, but apparently attempting to paste terminal output in this forum flags you for a temporary ban?