Okay,
So the folks at GitHub had a good workaround. I just confirmed it in a VM.
In the live environment before running the installer, edit /etc/calamares/settings.conf and move -fstab down several lines until it’s immediately after - dracutlukscfg as seen here: [settings.conf] Move fstab after luksbootkeyfile · calamares/calamares@232a78b · GitHub
The tradeoff is that you don’t get the graphical LUKS password prompt from Plymouth.