On Gentoo, for a couple of years, I used an initramfs compiled into the kernel to boot via EFI_STUB with full disk encryption. It's possible. It's been a while.

On Gentoo, for a couple of years, I used an initramfs compiled into the kernel to boot via EFI_STUB with full disk encryption. It's possible. It's been a while. I don't remember it being very easy to wrangle. I don't use that laptop anymore, but I still boot via EFI_STUB on my desktop. It's super simple to set up when you're not using FDE. I don't remember there being any specific problem that make some crypto setups more difficult than others, with the caveat that implementing FDE at all makes EFI_STUB somewhat more complicated no matter what. Like I said, it's been a couple of years since I figured all that stuff out, so the passage of time may have softened the terror of configuration and clouded my memories.