Give me a break. There are thousands and thousands of modded VWs out there. Many are even modded by the VW dealer who sells things like software chipping as an upgrade such as REVO, GIAC, and APR all of which I have seen at dealers. There are hundreds upon hundreds of examples of modded cars being serviced by the dealer and they are not voiding warranties. Also there are numerous examples of modded cars with cam followers with no increased wear.
No need to spread paranoia or be scared of one's own shadow. Saying things like: "You are risking sever damage to your car", "unless the add on is approved by the factory" "an approved performance provider" sounds like scare tactics to scare people into believing how you believe. Stop trying to grow fear.
If you believe that, that is fine, but the facts do not support severe damage due to modding, or voiding warranties, etc. at all. The dealer cannot "void your warranty" anyway. Your car is still covered. If there is a failure due directly to the mod then those specific fixes due to that failure could be denied if the dealer really wanted to. It has nothing to do with the rest of the car and everything is still under warranty. And that is only if the dealer was not mod friendly, and only if the dealer wanted to deny the claim.
Dealers vary widely in how they treat modded cars. Talk to the dealer service dept. to see if they are mod-friendly. But for Pete's sake, stop the scare tactics. Spend the time researching the facts instead.