Well, it's a pilot manual not an engineering one.
Exactly. We write flight manuals to give the pilot the limitations and operating information/procedures they need to fly the aircraft as designed & equipped. We avoid providing additional information which is not necessary, and may actually dilute the pilot's attention to what we need them to know. Sometimes in Section 7 (Systems), or a supplement, this information is provided, but not if it will have no benefit during flight. Pilots are greatly encouraged to read through the type certificate data sheet, and maintenance manuals for more detailed information - in between their flights!