Paul Palmer's suggestion has a great aspect that I'm surprised no airline has picked up on. Board elites in economy BEFORE the front cabin(s)! They have to walk through the front cabin to reach their seats. Why not let them on - they tend to know the drill, so it should be fast - THEN board the front, while they're settling in, and THEN wait EA/FA/AA's five minutes? That would reduce aisle congestion, not delay F boarding enough to matter, make it easier for FAs to take care of service while not making elites cool their heels, give elite FFs in economy time to settle in before the herd arrives...

The only downside I can think of is that some first-class passengers want to be FIRST in everything, even if they don't know why.