In an ordinary court, if a lawyer knowingly submitted false evidence and is caught, wouldn’t a judge have the power to immediately throw them in jail?
For any length of time?
Inherent contempt is generally not used to punish, it is used to compel. Short stints for punishment, for example outbursts in court. A few days to cooll off, chill out.
What FISC can do is forbid specific individuals from appearing before it. There is no sign it has taken this move.