Modern Vespa

2020 GTS300 Supersport HPE. I keep getting bad roller or clutch rattle at low speeds when accelerating slowly. Only 6,000km on the clock, had Dealer 1st service at 1,697km & they "Stripped, checked, cleaned & reassembled belt drive & rollers". They couldn't find any issues. It seemed to be fine for a while, but came back slightly, then about 5,000km started to get very bad again. I did a service the other week & took the opportunity to clean & deglaze the clutch pads & bell with some 60grit sandpaper (didn't inspect rollers as I couldn't find part of my flywheel-holding tool ). It totally disappeared for about a week, but again has started to come back.

Is this a common issue? Is a bit of roller/clutch rattle just to be expected? Do I need to be more aggressive in deglazing? Surely the rollers aren't done already @6,000km?

I think you need to be methodical and complete in your diagnosis here. Given that the clutch work you just did improved the situation for a while, get all the tools together, disassemble the transmission parts, and check everything.

It could be sticking rollers, which are inexpensive wear items and which I would replace simply to rule the old ones out as part of the problem. It could be a broken clutch spring or gummed-up clutch pad pivot point, and when you roughed up the surfaces it allowed the other clutch pads enough grip to compensate temporarily.