Hi biotech & neuro enthusiasts; how does BCI overcome mind wandering?

Hi there, here is a discussion topic I can't get out of my head and is completely unrelated to my current field of SaaS. As a psychology graduate who used to focus on neuroscience, I am recently getting blown away by the developments in brain-computer interface (BCI, e.g. Neuralink) and consider going back to school just for this! Whenever I imagine potential capabilities of BCI technology, I hit this dead-end question regarding how it manages to overcome mind wandering. Given that Neuralink seems to function somewhat accurately so far -of course in relatively less complex tasks-, the researchers must have got the system distinguish between mind wandering and decisive thoughts. Any thoughts and comments? Thanks!