Unless FinCEN issue clarifications, I'm inclined to think that all board members meet the definition of someone being a pivotal decision-maker having substantial control. The definition of the position is in relation to the entire HOA, not simply the individual's role within the governing board. There's another reason the BOI filing is going to be a big problem for HOA's and small businesses with multiple Beneficial Owners, because the filing needs to be updated within 30 days when any information changes (including the expiration and renewal of the form of iD used in the most recent filing).
I also read in one HOA-focused article that HOA's should consider amending their by-laws to make "willingness to provide the information for the BOI filing" a requirement for serving on the board. (Otherwise, what happens if someone is elected to the board and they refuse to furnish a drivers license or passport for the update to the BOI filing?). It's difficult enough to get qualified people to serve on HOA boards to begin with - the BOI filing requirement only complicates matters even more.
I don't think this was the intent of the original legislation, and I'm hoping ithe effect on HOA's will be changed or clarified. But until that happens, HOA's are stuck with the requirements in place. .