Sorry I don't have as much experience as you or that you felt I was dismissing you. Either way like I said it's up to the OP to read and decide what's right for them.
Many feather dusters have very long feathers (like tail feathers) and the chicks can get caught or twisted up in them. If you must use a feather duster it's best to trim some length off the duster to shorten the length of the feathers (plus the quills are thicker and less likely to twist around...
Definitely zip tie the cardboard in place, to minimize any gaps between cardboard and wire, and I'd skip the feather duster. Chicks have gotten tangled and killed in them before, and it doesn't really add anything (as they have the heat plate) unless you're dealing with a single chick with...