IMO it doesn't really matter where you put it, as long as it's high up that's where they're going to prefer. So basically I'd locate it where it's most convenient for humans to enter the coop and do maintenance. My gut says don't put the bar inline with their chicken door, because that's where you'll get the most poop accumulation and they'll be walking through it going to/from the doorway. Soft landing is definitely a good idea, just don't know how soft sand is going to be in that space with a hard floor, since it doesn't look like you'll be able to make it very deep for them without spilling over your chicken and human door thresholds