If a user configures their install with Full Disk Encryption on a device using the Surface Aggregator Module, they are unable to enter their passkey with the built in keyboard with the default Silverblue initramfs. After reading linux-surface: Disk Encryption I was able to resolve this by writing the following to /etc/dracut.conf.d/surface.conf and running rpm-ostree initramfs --enable:

add_drivers+="surface_hid_core surface_hid surface_aggregator_registry surface_aggregator surface_aggregator_hub pinctrl_amd"

I don't know if this configuration is possible in the image generation process, but if it is it would make the process of bringing up a Silverblue/uBlue install on a Surface using the SAM (like my Surface Laptop 3 AMD) much easier.