Hacky and horrible, but it makes the thing work.

lubuntu/modules/bootloader.conf

@@ -30,4 +30,4 @@ grubCfg: "/boot/grub/grub.cfg"
 # setting the option here, take care to use only valid directory
 # names since no sanitizing is done.
 #
-efiBootloaderId: "ubuntu"
+efiBootloaderId: "lubuntu-next"

lubuntu/modules/packages.conf

@@ -3,5 +3,8 @@ operations:
   - remove:
       - calamares
       - '^live-*'
+      - linux-generic
+      - linux-image*
+      - linux-headers*
   - install:
       - linux-generic

lubuntu/settings.conf

@@ -18,13 +18,11 @@ sequence:
   - locale
   - keyboard
   - localecfg
-  - luksbootkeyfile
   - users
   - displaymanager
   - networkcfg
   - hwclock
   - services
-  - initramfscfg
   - initramfs
   - grubcfg
   - bootloader