Can a meditation course adapt to how a session went?

Yes, within limits that are deliberate. After a session you can reflect on how it landed, and that reflection shapes the next one: how much guidance you get and how it is framed. What it does not do is change what the next session is about or reorder the arc, because the plan is what makes it a course rather than a run of unrelated sessions. In StillMind the adaptation happens inside the plan rather than to it. If a reflection suggests you are having a genuinely hard time, it is never quoted back to you in a script, and the next session softens.