For dry fire practice sessions it's going to be DAO unless you rack the slide.
For live fire it's not hard to learn to lower the hammer safely. In practicing for my IPSC and IDPA matches I often run multiple mags of "first double" drills on targets where I lower the hammer onto the live round and then holster or from a low ready lift up, sight, shoot two. First round in DA and second is SA. I then lower the hammer and repeat the drill. It takes no more than four to five seconds to prep the gun and re-holster in a calm and safe manner.
It's also a more applicable drill method for the intended usage of your Shadow since you've already got the gun.
And unless you're a peace officer that uses a DAO in your duties it's likely that you don't REALLY want a DAO as a personal gun. And even if you do then by rights you would want to replicate the same gun and trigger pull for the drills to mean much.
Another option for a DAO gun would be to develop an intrest in DA/SA revolvers and just ignore the fact that the revolver even has a SA mode.