we could be 99.9% screwed and the remaining 0.1% could be caused by donating to SI and it discouraging some avenue to survival.

Actually the way i see it, the most stark symptoms of SI being diseased is the certainty in intuitions even though there isn't some mechanism for such intuitions to be based on some subconscious but valid reasoning, and abundance of biases affecting the intuitions. There's nothing rational about summarizing a list of biases then proclaiming now they dont apply to me and i can use my intuitions.