I lean toward recommending people to fill out a form at 0%, just as a safety protection.
I think a few years ago someone noted a case of a small plan, with a safe harbor match. owner is the only who defers, so is the only who gets a match.
no other contributions made, so owner got the monopoly "get out of top-heavy free" card.
now, a few years after the fact the NHCEs go to the DOL and say they never even knew about the match, and they would have deferred had they known.
who do you believe - the owner who said he gave out the info or the NHCEs?