[rich2202]

Does the Flow Control, In-Line, 1/4" tube, press-in (am-2690) restrict flow both ways? If so, it might slow down filling of the piston when it is extending by restricting the flow on the exhaust side.

The 1/8 NPT Male to 1/4 Tube, Elbow Meter-Out Flow Valve (am-2897) says "while the opposite flow is not restricted". Assuming it can be plumbed in the correct direction, it would meter air going into the piston, and unrestricted flow of air going out of the piston. If not, it might be able to be used on the other side, and restrict air going out, and unrestricted air going in.