/etc/crypttab not updating in initramfs

I have a new installation of ubuntu 22.04, with full disk encryption (LUKS) and ZFS picked from the ubuntu installer options. I need to make some edits to /etc/crypttab so that unlocking my drives works in an automatic way (fancy usb auto unlock), but the edits I'm making to /etc/crypttab aren't persisting to initramfs. What I'm doing is: - Editing /etc/crypttab - Running update-initramfs -u - Rebooting my machine into the the system that asks for the LUKS password (initramfs) - Checking the contents of /etc/ but crypptab isn't there. Have I got my concept of how this works incorrect? I need to persist some version of crypttab to the loader but it isn't working. Any pointers to what I'm doing wrong?