Devsfan's practice is both prudent and common. If it was the way you had done things in the past, you would do it in this instance as well. If your past SARs have not mentioned signatories and principals, then you would not need to change it solely because one of the principals was a board member.
I'm glad you are not really facing this situation because asking the question proves you already understand that any third party reviewer could make a big deal out of the fact that you did not mention that a director was involved. On they other hand, your CEO could make a big deal out of the fact that a board member was "outed" gratuitously.
If the situation was real, I would probably discuss it with the CEO, but it would be after the decision to file was made and the paper trail was perfected. Then, I would point out our past practices and let him or her make the decision to mention or not mention the board member and note his or her status in the narrative.
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In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.