[Jake Raby]

By the time any valve timing deviations occur the engine has already been subject to foreign object debris from the failing bearing that HAS to have degraded enough to allow for the deviations to e measurable. Collateral damage from foreign object debris wear metals from the IMS bearing have always been the primary modes of engine failure with IMSB failure.
There are lots of issues with measuring camshaft deviations and I know these because I have tried it.. Wait till a tensioner gets lazy or you have thick oil on a cold morning, or under heavy deceleration. What's is supposed to happen in theory doesn't happen. False positives would happen daily.