Slightly Longer Response:
For Custom Subliminal Designers,
the question you need to ask—and ideally ask through both analytical (left-brained) channels and intuitive, experiential (right-brained channels)—is:
‘What does this module do?’
If you’ve asked it well enough and arrived at a sufficiently solid response(s), then your next question is just:
‘Do I want that influence in what I am creating?’
Ultimately, people who, for whatever reasons, are motivated or willing to ask those questions, will be the ones who get the most use out of customs.
Shorter Response:
@gdbdboy said it right:
question: So, ‘who or what defines the ‘desired result’?’
response: The Listener.
Also: Modules in a custom will inspire both individual results and synergistic, integrated results. (In other words, each one will mix with the others, and it will also do its own thing sometimes. BOTH.)
The ultimate organizing principle for any subliminal custom or Main Store is: YOU, Your Mind, Your History, Your Values, Your Lifestyle Choices.
Feed a carrot to a rabbit, and the carrot is digested and transformed into a rabbit body.
Feed that same carrot to a rhinoceros, and it is digested and transformed into a rhinoceros body.
In both cases, the Vitamin A in that carrot will lead to improved eye health. But in the first case it will be a healthy rabbit eye, and in the second a healthy rhino eye.
You are the ultimate organizing context of the programs you play.