No, typically they’re just sensors on a cranial harness.
Do you mean EEG stuff, or are you referring to like, inter-cranial implants, which I don't know shit about?
Yes, there’s no real advantage to making it permanent other than convenience. However this convenience is imo massively outweighed by the very real possibility of meningitis. It’s crazy that they got approval to transect the blood brain barrier for an implant. Other implants do this, but that risk is being weighed against things like potentially deadly seizures, not mild convenience.
Do you mean counteracting potentially deadly seizures, or causing them? Also, there's probably too many other problems to list about the technology generally, but since you seem like you know what you're talking about, could you give me like, a kind of general overview on BCI, or your opinion? Maybe like, challenges, what you see as being the most promising stuff, that sort of thing?