grenv: I agree. In regular backgammon, a double tap can be devastating. In crowded (though I, like grenv, have limited experience with the latter) closing up the inner table is important, as you do not want your opponent using those extra pieces to create a strong "back" position (more than one point made in your inner table). The latter can easily lead to getting hit/locked up on the bar toward the end of the game, which is when that really matters, in crowded.

Having said all that, I have completed all of 4 games of crowded (though my record is 3-1). So take that for what it's worth.