I have no idea on what a dry aged shoulder would do, maybe marketing .but Lamb can be dry if its too lean.
I cook shoulders to feel rather than temp.
I take the lamb to just under bone pull stage then wrap in foil, back in the cooker for a few more hours, then in a cooler for up to 4 more.
Using a pan with water in it and catch any juices, pour back over it when wrapping.
Don't let the water dry out
If I took it to temp I would be hitting for 194f finished, so maybe wrap at 180f
Q temp of about240/250f
Hope this helps more than confuses.
I will never be over the hill.
I'm too darn tired to climb it.