I have never realized the the potential of LVM and never really cared.
In fact I have considered LVM to be an unnecessary complication but as @openminded recommends LVM - I am prepared to put aside my prejudices and embrace LVM for this lesson.
I should apply myself to learn to create the LVM structure by hand, I think this will have to wait as
manjaro-architect
is a great tool and I don't feel like diving into LVM just yet. Manjaro Architect can be added to the running instance of a live ISO. Ensure you have a working mirror and the package databases. Do not use the update argument or the gui as this will attempt to update the live ISO which makes no sense at all.
pacman -Sy
pacman -S manjaro-architect
The base install needed to implement secure boot
/efi
and modify fstab $esp mount to /efi
Don't forget to verify networking