It's kind of a tricky problem to solve. The current design mimicks the ergonomics and dimensions of an A4. If they create a "low profile" rail for the top of the receiver then whatever sights you mount will be too low to get your eye behind. Unfortunately the Ruger barrel is ~ .7" lower than that of an AR. The best compromise I've seen suggested is to build a .7" riser that mounts onto the top rail of the freefloat tube so that the receiver rail and the barrel rail are all the same height. It wouldn't look as clean as the continuous rail you posted above, but at least rail mounted sights would line up.