Understand the wish to play it without the use of it, and sounds like raising the charm thing is a fine optional choice as well.
Thinking in just this single case it might be fine to pass it, just to keep it simple.
Like no matter how much bimbo energy she already has had before doesn't influence anything. what matters is the action of using it after the 6th S-link. so no matter if her bimbo stats were 1 or 10, it's just a required thing to do at this point so the story would could just progress as normal.