I read this at the time and was congratulating myself on my new Sunrace MS8 cassette being silent – until Wednesday, when I noticed bad creaking noises in the middle gears only, not at the extremes of the cassette. All new drivetrain, just over 400km on it. Cassette lockring was tight, no indexing or B-screw issues.
Took off the cassette, opened up freehub (old Pro II) for a look while I was in there – to find one spring had snapped at the hinge and was lying under the pawl doing nothing. Replaced, reassembled and reinstalled cassette. To avoid confusion, I did nothing to the cassette other than wipe down the freehub/cassette contact surfaces with some kitchen paper, to remove the small amount of dust and dirt. So, no lubing of cassette rivets etc.
Result? No creaking. Inconclusive, can’t see why the creak would only be in the middle gears if the broken pawl spring was to blame – hasn’t happened when I’ve broken springs before. The creaking was definitely worse in the four gears on the middle unit of the cassette. Guess we’ll see what happens in another 400km.