Should I wait for roots in rockwool (tray and dome), or move directly into DWC/Aeroponic System to grow roots

With a seedling the taproot should become visible fairly soon and really doesn't need to be kept in a dome. Seedlings do better with fresh air IMO. Domes are much more important for cuttings. I like to get things setup in my net cups fairly early. From there you can set the up however you want. You can just irrigate it a few times a day until roots show. You can setup in your rez. Just make sure you adjust your water levels so your cups get moist but not soaked to promote a little wicking without drenching the rockwool. Rockwool works best when wet but not soggy.

I do rockwool cubes into aerocloner into RDWC. I let my cubes sit on a heating pad until a root is visible on the bottom of the cube, then I throw them in a neoprene collar's slot in the aerocloner. IME, if I move them before, the cubes will stay way too saturated and stunt the seedlings. Basically, I wouldn't move the cubes from their isolated spot until you'd actually be getting an aeroponic effect by moving them (or can guarantee they can breath even if your cubve stays saturated).