[EDIT: simplified and corrected]
I would like to use the same method as Raspbian install which relies on
dd deployment to a µSD. Meaning, from a minimal image file, deploy the "augmented" Raspbian system partitions with
dd on a SD card, resulting into two partitions and their files.
Is there a way to augment (inject files) the image blob file?
(The augmented image file won't fit into RAM)