apple_set_os kernel parameter fails

[vanya-robertson]

I have followed the instructions for Enabling the iGPU.
Setting apple_set_os in GRUB_CMDLINE_LINUX_DEFAULT causes glxinfo | grep "OpenGL renderer" to return the Intel card only when running the backup initramfs. When running the default initramfs, my console just fails to boot.
Please advise how to solve.

[Redecorating]

what mac model is this?

Maybe try regenerating the initramfs when you boot the fallback initramfs, so the default initramfs will have any modules needed for the igpu as well

[vanya-robertson]

I was running mkinitcpio -P after grub-mkconfig -o /boot/grub/grub.cfg

[vanya-robertson]

It is a 16,1 Macbook Pro.

[vanya-robertson]

I was regenerating initramfs before booting into backup. When done from the backup initramfs, it worked. Why would this be?