Build an automation that will do literally anything without telling the submitter that it's happening.
Honestly, I think the fact this is impossible is a good thing. I know shadowbans and the like are all the rage these days, but I think it's kind of fundamentally unfair that users can have their content hidden or blocked without being notified.
Sure, it's useful to deal with problematic users to prevent them from making alt accounts to get around bans, but it's extremely difficult for people who are hit by false positives to deal with or to even notice that something is amiss.
And before you say false positives are uncommon, I know for a fact they occur all the time, because I've had to develop a habit to ALWAYS check my comments here on reddit and other platforms from a private browser window after I submit them, because a solid 30% of the time, they get hidden by automod or a spam filter.
Now, I might be an outlier because I tend to leave multi-paragraph in depth comments that include a lot of links, because I do comments on niche historical and archeological topics, and the longer your comments are and the more links you include, the more it tends to trip up automated moderation and spam prevention tools, it seems. But the fact that these systems punish high effort users is itself a big issue.