You present the question as a *dilemma* with only two choices:
a) Give credit to person P's idea I. Discredit the person P by repeating accusations A and judging them believable. Risk criticism for stirring up irrelevant drama.
b) Give credit to I. Be complicit with P by staying silent on A.
But is this really a dilemma? Maybe you're mixing up two topics. Why not write *two* posts, one for each topic?
In the first post you discuss the accusations A. Explain why you feel the need to give those accusations credibility by repeating them publicly and judging them as believable. Let the discussion take its course. Wait for the result. If you really believe that these accusations should be aired here, then do it properly. Give the accused a proper chance to defend themselves. Make sure that you understand your own motives.
In the second post you then discuss the idea I. Any discussion about A would be off-topic for this post about I.
I'm reading your post as an example of an active learning strategy. At what point do you verify that your concept is correct? Do you stop when it feels "satisfying and like the concept has clicked into place"? Or do you test your concept, for example against textbook exercises?