Did you ever receive a response?
I'd like to know this also.
I did receive a response but it contained factual errors. I had a revised clarification drafted and sent back to FinCEN per their procedures.
Ty for the update, keep us posted!

Will do. They are suppose to respond within 30 days but it took more like 50 on the first response. The clarification was sent back about 3 weeks ago. On advice of counsel I decided not to make their response public while it is still openly being reviewed.