While none of the attempts to synthesize the material have produced any conclusive evidence of superconductivity, those who claim that the material cannot be a superconductor have also failed to produce any conclusive evidence for this.

The confident tone of the more recent papers which did not measure any superconductivity did not have any solid grounds, because they did not contradict the earlier theoretical papers.

The theoretical papers have concluded that superconductivity, if it exists, would appear only in certain hard to obtain crystal structures, which have not been obtained in the studies that have not found superconductivity, so those results were as expected.

Therefore whether or not some compound based on doped lead phosphate can be a high-temperature superconductor is a still open research problem.

It is not some kind of perpetuum mobile quest that can be automatically flagged as impossible.

One must take also into consideration that the Koreans may have intentionally published a misleading recipe, to prevent replication.

When the first high-temperature semiconductor has been discovered, the team which did it has intentionally misspelled in their published research the element name yttrium as ytterbium, in order to fool everybody who will try to replicate the research, but to still allow themselves to claim that they have priority in publishing, but they have just made a honest spelling mistake in their published paper.

So if the Koreans have been intentionally misleading, they have just followed the example of the USA research in superconductors.

My justification for flagging, rational or not, is that I know enough to make reasonable decisions about what articles should not be widely distributed, to prevent the growth of disinformation.

Claiming the Koreans made a fake mistake to throw people off while getting publication priority isn't reasonable disagreement. It's within the realm of possibility they are playing 3D chess but I think the consensus opinion is reasonable: they didn't provide enough info to reproduce what they saw, and what they saw likely isn't room temperature superconduction. Since then we've seen experimental groups "confirming superconductivity" (which they didn't) and theory groups claiming the chemistry is consistent with superconductivity, but theorists will come up with theories for anything, often by just tweaking some variables until they get something that appears plausible.