Rob
I am not familiar with the Legacy hydraulic system at all, so I don't know what knowledge transfers and what does not.  The schematic for the 360 pump actually shows the return to reservoir passing through a very low pressure check valve.  I don't recall seeing this installed on my pumps and find no reference to it in the parts list.
Having an accumulator in the (360) system would be nice in terms of both increased leak tolerance and provides a softer cutoff as you mention.  The dynamics are quite interesting.  I use a second pump on a test stand for trouble shooting and checking overhauled cylinders before placing them back in the plane.  The relief valve settings and pressure switch settings have to be quite different to obtain the same final system pressures.  The test bench plumbing is short and stiff.  The plane on the other hand is much softer (with 30 feet of tubing and hose) takes much longer to reach equilibrium.
Chris