The B division issue has been raised in Australia recently. We don't have enough players to risk running a separate division which would draw people away from the main IFPA event so its a tricky issue.
At my next event I'll run a B division as part of the main event. Everyone does their qualifying in the main draw. Lets say there are 16 through to the open finals. If you come 17th that is your IFPA placing for the overall event. However after that is finished you get a shot at B division providing you meet eligibility criteria (in this case, you need to be <= 1500 rating, and >= 1000 rank). The top 8 guys who don't make the final, but meet the criteria go into a B division final. Its important to note that B division has no impact on IFPA ranking for the event, its simply for the fun of competing with similarly skilled players.
If you meet the criteria but make the open finals you are ineligible for B division.
Keeps it fun, and doesn't spoil the total points available. Obviously not needed at the big events in the US, but since in Australia we struggle to get 50 rated players to even the biggest events, the back of the field can have some fun and experience finals without having to compete against the same 10 guys every time.