I've been saying for a long time that after the elite boarding, they should start with the window pax and those seated in the same row traveling with them, which would keep the aisle pax from blocking the aisle while the window and center pax get settled.
There's still nothing like get the plane boarded quick or miss your flight to motivate the pax.
That would help some, but even window pax will need to stow their bags in the overhead bins. Boarding back to frank would produce better results IMO.