EDIT: Well, I see you guys beat me to it! But here is another idea, for what it's worth:
Well, I don't use track planning software, but here's a sketch. This would be the top portion of your yard (nearest the aisle). The top two tracks handle trains arriving/departing (the train parks on one track, the other is a run-around). The rest of the tracks on the right side are regular yard tracks--I didn't bother drawing the majority of them. Both of the two diagonal tracks on the left meet the inner loop main line, preferably to the right of the double crossover. So the idea here is that while the switch crew is busy moving up and down the yard ladder (right-hand diagonal track which all the yard tracks come off of) an inbound or outbound train can still access the top of the yard by using the bypass track (I believe Armstrong calls it a thoroughfare track) on the left. And, the switch crew can easily access those top two tracks from the yard ladder.
This will, of course, shorten your yard, and your longest train will be dictated by how long you can make the designated arrival / departure track. However, it can potentially double the amount of fun your yard can produce at any given time, since you can have two people working in without one having to wait for the other to be done before doing their own task.
A problem with this design is that your yard does not have much of a lead. That means that a switch crew moving a long cut of cars could end up backing onto the main and getting in the way of the arriving/departing train after all. I don't see an easy fix for this, but it would not be too much of an inconvenience for people to simply remember to take fewer cars at a time and not back onto the main.
Another idea that comes to me just now is to expand the top section to three tracks. The third will be a little longer than the others and can be the A/D track. The top one would host cabooses. The middle would be a shared runaround for the other two. Since you only access the caboose immediately after a train arrives or immediately before one departs, this should work OK from the perspective of the switch crew staying out the way of the other train.
One last thing: at present, you have the yard ladder leading through one side of the Ross 4-way. This creates an awkward S-curve. It might be better to have a switch in the ladder (possibly a curved one, rather than a #4 or #5) and let the 4-way originate off the diverging leg of that switch. This, too will cost you some length, and might not be worth it after all, but since you can use the software, it costs little to experiment.
