The notion that Work Track 4 already covered all the know evidence of harm is not accurate. If the Board were willing to rest on what Work Track 4 had, it would never have initiated the NCAP as an OCTO project.
Board never considered WT4 output, since it will only be sent to the Board in the final report. And due to lack of consensus, most discussions in WT4 will never reach Board at all, so saying that it was considered is too far fetched.