I was going to add that I also had some chatter on an old bike and changing the oil was the fix. Wet clutch systems can be picky.
When you cut open the filter, of you do, use a set of snips. No saw. Rinse with gas and cut the pleats off the filter and open them up. Filter the diluted oil gas mix though a coffee filter. Anytjing more than pixy dust and there is an issue. Of its magnetic that's clutch disk, not ideal, it should be mostly non magnetic from the friction pads.
Imo unless there are larger than dust like pieces, think glitter or smaller, it's fine.
