Any question answered...

I think the one with the L goes on the left shoe. The one with the R goes on the other shoe.

I don't think it's about float. Time cleats are asymmetrical so they only unclip outwards or something. But I have no idea what I'm talking about

Correct. To get a 'firmer' release with Atac cleats you put the L on the right shoe and the R on the left shoe.

But that means it bloody doesn't matter where L and R cleats go as it's a matter of personal preference. Geeee...