When I rebuilt my 200 I fitted a sump magnet plug, and fitted some small Neodymium Block Magnets around the filter. They only cost £4.00 for five, and are extremely strong. I did this on the grounds that it could do no harm, and might do good.
On the first oil change, at 800 miles, there was a lot of very fine grey sludge on the drain plug, from the rebore. I didn't strip down the old filter, but if they remove even a little of this fine metal dust from the oil, it's £4.00 well spent.
The second oil change, at 1900 miles total, still produced some of this dust.