What I do is add the banned user to "Banned" user group that has the
React to All Posts
disabled.
ACP -> Setup -> Options -> User discouragement and discipline
View attachment 280089
I am not sure if this will carry forward to a thread ban itself though.
If not, I do agree that probably a thread ban should stop ANY interaction on that thread.
I luckily have not been cursed with having any users needing that level of moderation yet.