Exporting the .dae is unnecessary; you can place the object directly into a .scn file:
.dae
.scn
Create the new .scn file in the .scnassets folder, then drag the .dae file into the scene.
.scnassets
open your DAE file in the SceneKit scene editor, then go to the Editor menu and click "Convert to scn file format".
Your artist won't be able to export a scn file from their favourite tool. You'll have to use Xcode to convert a DAE to SCN.
