Agreed - call FinCEN. Absent clear guidance, I wouldn't exempt, that slope is just too slippery for me!
You could always submit a written request for clarification. This would be the safer course of action. Examiners and auditors can't argue with written guidance. The last time I did this it took about a year for a response.
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Life without Jesus is like an unsharpened pencil - it has no point.