I would check that the sheet metal dust shield is centered on the hub and therefore the drum may hit it occasionally and make noise. Look at it carefully and if you find a spot where it is hitting you can usually take a hammer and a long screwdriver and tap the dust shield to center it.
The next culprit could be the grease trap inside the clutch. If you don’t have the washers / spacers installed correctly it can also rub on the drum.
One way to keep the outer dust shield from getting off center is to remove the snap ring and the shield and put a small amount silicone sealer around the hub and snap ring groove.
Install the clutch making sure things are centered. Don’t start the engine until the silicone is cured. It depends how closely your tech guy follows the rules whether it legal or not. In my opinion i’s not a performance improvement so who cares?