Fascinating. As a child, I semi-reluctantly learned vedic chanting when staying with relatives over the summer. It was very interesting to understand the “algorithms” behind the techniques they used to have us memorize each “shlok”. As the author says, these served an important purpose to transmit knowledge to future generations when writing materials and books were scarce and delicate.
The idea that memorization was used due to a lack of writing material is just a modern and shallow interpretation. The ancients considered written text as less authentic, and rightly so. Oral knowledge is spread among the populance and can not be destroyed or distorted by few actors.
If anything, purely relying on oral transmission means that the further that knowledge moves away from its source, the further variations and slight changes that will occur... intentionally or unintentionally. It is the reason why when you try to collect old folk tales or mythological stories, it is difficult to figure out the canonical version of it.