Continentals do suffer from the same problem.
We started to get aluminium in our 0-200 oil filter.
For ease we removed the engine and sent it to Richard Isenberg (top man and recommended by me).
If I remember rightly the cause was the pins comming loose in the gudgeon pin and a build up of air pressure due to heat forcing them hard against the cylinder walls.
Running sweet as a daisy ever since and that was quite a few years ago.