Scale and spelling meant little to the AEs: they would double the same single sound consonant simply to fill space on a piece of carved stone or they would reduce glyphs while still keeping the sound intact if they were strapped for space. Look at the four ways in which the phrase 'Ma Hru' (justified one, signifying a person is deceased) was written on stelae and coffins, the choice often determined by the position of the glyphs on the masonry or woodwork to the parameters of the surface.
Neferkare Khendu's inscription contains a lot of glyphs. This is, in itself, one of the reasons for diminishing scale. The artist was working within the parameters of a pre-determined space for each cartouche, driven by the aesthetics of the overall design.