Dual boot linux using FDE and an LVM

my goal is to have this particular laptop running a dual boot setup of Kali Linux and Endeavour with the BlackArch repos. I know how to do this with Kali and Endeavour alone, but I am not sure how to finish the installation to bring the other OS inside the encrypted LVM. So with Kali, I create a small efi (1gb of a 500gb SSD) - /boot/efi/ flagged for boot; proceed to create encrypted vols and encrypt the entirety of the drive minus the efi; THEN create the LVM, creating vols for root, home & swap (meant to be basic, as much as THIS is basic), and at that time I generally create the same for the Endeavour install but dont use them; assign root/home, and let the system install. Rebooting brings the exact behaviour I wish for: the machine asks for a PW to continue almost immediately. Then it will unlock and go to the GRUB, where I would like the option of choosing Kali or Endeavour (or a backup, as I was going to use btrfs). But this is as far as I’ve been able to get. I cannot for the life of me figure out how to complete the install when running the 2nd install’s ISO, going into Calamares and assigning the parameters to get the results mentioned previously.
I wouldnt think this is an unusual approach, but I cannot find info on how to do this that doeswnt involve a bunch of irrelevant mess about saving Windws, or installing Ubuntu, LoL, srry…

anyway, any guidance to unlock this mystery, or simply a confirmation that this actually cannot be done with these installers, would be much appreciative. As far as the rest of the install and integrating BA - this is not a problem, I run it currently. My goal is simply to add a ‘bare metal’ instance of Kali to dual-boot the Arch-only laptop. Thanks again!
Hardware information:
I am running an ASUS ROG Zephyrus G15 Ryzen 9 RTX 3080 32GB with a pair of Samsung 970 EVO PLUS 2TB SSDs, 165GHz 2560x1440

Although I have never tried, I don’t think Calamares supports installing into an existing LVM volume.