Not true for my customers.
I actually send every one of my customers tons of info so that they know everything about the control valve and softener. It includes how to program, assemble, install, troubleshoot and repair. There are pages of parts breakdown with part numbers and pictures of all parts and text info and instructions of how to replace a part or replace resin etc. etc.. And how to change the K of capacity and the salt dose when hardness, iron or the number of people in the family change.