Forgoing context (eg cached judgements) is highly inefficient. Having to individually evaluate each bit of chaff severely undermines the ability to have productive discussion. Looking at the larger picture, destroying the discourse with nonsensical spam seems to have become the entire political game at this point. If we want to have any hope at actually addressing the issues facing us in good faith debate, we've got to upgrade our discussion forums to mitigate the noise floor.
[0] If your criticism is that ersatz cloth masks are ineffective, then the conclusion is to push people towards real N95/P100 respirators rather than just rejecting the insufficient approach.
If someone is easy to manipulate to spread misinformation about Ivermectin being effective for treating COVID in humans, do I really want to listen to their opinions about (for example) technology or are they horribly misinformed in that as well?
Is it unfair? Maybe.
But why do you need a tagging system for that? If they're constantly spewing "reality-denying" comments then surely you can tell by the comments? Or do you find the tagging system useful for when they make plausibly sounding comments, so you can dismiss those with prejudice as well?