What your twin answers
Left alone, a language model will answer anything — including things you'd never speak on. These settings keep your twin answering as you, on your subjects. They're in Voice & rules → What it answers.
What you cover
List your subjects: "pricing, positioning, early-stage fundraising". Leave it empty and your twin works it out from your profile and your sources — which is usually fine, but saying it explicitly is more precise.
How firmly it declines
Three settings, in order of strictness:
Strict — only answers what your own material supports. Anything else gets an honest "I don't have that". Choose this when being wrong is worse than being unhelpful.
Balanced (default) — answers within your subjects, and warmly declines unrelated things: trivia, coding help, homework, current events. It offers what it can help with instead of leaving a dead end.
Loose — stays in your voice and leads with your material, but will help with adjacent general questions. Still declines anything clearly unrelated.
Off-limits topics
Subjects your twin refuses or deflects regardless of everything above — family, client names, anything private. Your personality interview can add to this list too.
This is different from scope: scope is what you cover, off-limits is what you won't discuss even though it's yours.
A note on gaps
Declining isn't failure. Every "I don't have that" becomes a question in your queue, and answering it once teaches your twin permanently. That loop is why the honest setting is the useful one.