Is there a way to get a LUKS keyfile in initrd.img/initramfs, with jxself's kernel?

Having tried two different ways, through both links referenced in this thread:

https://trisquel.info/en/forum/how-add-luks-key-file-initrdimg-initramfs-helpful-if-you-dont-want-enter-your-password-twice

I have been unable to successfully get a LUKS keyfile to load properly with the 4.9 lts kernel. It works just fine with the original kernel, but whenever I try to boot the machine, after having created a keyfile according to the instructions, the boot process hangs, with a line of code like this:

"""
[ 0.004000] []
[ 0.004000]
[ 0.004000]---[ end trace 4eea2a86a8e2da22 ]---
"""

This isn't the exact message that I got; I took it from a site where a user was getting a similar error, but I think it should be enough to diagnose the root cause. When I go to boot the old kernel, everything loads just fine, so I know that it's not a problem with the OS itself, nor with my GRUB configuration file itself. If it's a problem with initramfs or vmlinuz, how would I go about diagnosing it? Does anyone know of a way that I can do this with one of jxself's newer kernels, or do I just need to come to terms with entering my LUKS passphrase twice?