Question to those believing in speaker break in

OK.

But what about the distance between the speakers when placed front to front?

The sound will be much more quiet when placed without any space between. 

Yes, face-to-face reverse polarity will work - but what fun is that! I'd rather set them up normally and enjoy some music!

@jasonbourne52 ​​​​​​

Problem is that I have to listen at low volumes and that way it would take ages.

And that is why I am wonder about the space between the speakers. 

You don't need to be playing loud. To break in woofers, I tend to like playing 20hz loops, where the woofers go a far distance without letting out much audible sound. For mids and drivers, just play different types of brown noise at 50-60db through the night.  Then, use a full spectrum glide, like the one found on Ayre's Irrational But Efficacious burn in CD to tune everything up every 24 hours or so.

I would use this as an opportunity get to know the sound of your speakers and to listen to speaker break-in. Part of the enjoyment of Audiophilia is learning to listen. But, and this is not contradictory, try to listen to the music, not the speakers. Yes, I know, you just got them… exciting. But you really want to learn to listen to the music and thusly understand the effect the equipment has on it… versus listening to the equipment. The former is quantitative the later is Analytical. With the latter you can go off on a wild goose chase of detail and slam and find the music does not sound that great.