I wouldn't worry about it. I'm running 30mm on the rear and 20mm on the front
Mine have been on for over 2 years and 20k+ miles on original bearings with no ill effect so far but its subjective... these cars had had a varied lifestyle now they are cheaper to buy and have a few miles on them...
20mm is a little excessive, I use 15mm on the rear and 10mm on the front... that is on OEM ET32 RSTT's
to be fair, your motor does have a sick stance! What coilies you on, do you get any scrubbage at all?
What makes 20mm a little excessive?
i got some AP coilovers on order and am planning on goin 20 on the front and 25 on the rear still running the standard Avus alloys