That's of course not to say that fringe beliefs MUST be rigt, of course. But if I claim that it's obvious Epstein was murdered,am I spreading disinformation or am I dissenting? If I claim mRNA vaccines are potentially dangerous and that we can't just trust the clinical trials?
It's sometimes easy to sort fact from fiction with hindsight. There are certain facts that can be discounted as disinformation on the face of it. But it's very hard to entrust anyone with such power.
For an example of how this is dangerous, just look at how hard it is to criticize the state of Israel and its actions without being labeled an anti-semite (or a 'self-hating jew' if you are Jewish). This is an excellent example of how dissent in proximity to disinformation can easily get swallowed along. Bill Gates is not trying to poison us with 5G, but if people start removing such facts, they may also start removing posts that accuse Bill Gates of using his money and influence to pressure states into trying his experiments, e.g. with his disastrous ideas about education in the US.
Now I'm curious what your take is on "There is a pedophile ring run by democratic operatives who shield each other" because there's even more smoke around that fire (although of course it's not limited to Democrats).
A more illustrative example than "asbestos causes cancer" from your list would be "asbestos manufacturers are hiding the fact that their product causes cancer." There was a point in time where the conspiracy to conceal asbestos's cancer-causing properties was in a liminal state of knowledge: you couldn't read about it in the New York Times or even initially in scientific journals, but now it's simply a matter of the established record. It's certainly an "insane" idea (company executives explicitly deciding to kill thousands of people rather than endanger their profits), even when contemplated in retrospect. How would this idea have avoided a preemptive dismissal as "disinfo"?
> That a ridiculous proposition would require other ridiculous things to be true as well is not support, it is lack of support.
Those other things I pointed out w.r.t. Gates may seem ridiculous, but they are actually true.
There are very few arguments about observable facts that start with 'for the sake of argument' and then postulate something utterly ridiculous, to engage such an argument would require one to shift ones worldview into the realm of the insane and that just isn't productive.
If you want to postulate that argument you are going to have to come up with some proof, the burden for any kind of argument that is so far out there lies with the one making that argument, it does not lie with the people addressed to dispel it other than out of hand until there is even a whiff of support. That a ridiculous proposition would require other ridiculous things to be true as well is not support, it is lack of support.