Freewheel with front brake only is the worst of both worlds. If you're going to run freewheel, why not have both brakes so that you can take full advantage of the benefits of freewheeling, like the ability to bomb hills and charge up to traffic lights with (relative) impunity?

I'm not saying that God's going to kill a kitten if you do this, but really, what's the point? No need to pose. Let your freewheel flag fly.