When i create DataAssist pages i usually save the final situation as a preset. If someday i would like to make changes then i just create new pages based on my saved preset, make the changes and produce the new pages. Then i just replace the old pages with the new ones.
I'm using DataBridge so i'm not sure if the DA standalone is also able to save the presets but i think it can.
Maybe using saved presets can also help you to do what you want.