the egr cooler has to be allowing quite a bit of coolant in the intake for it to be getting past the rings to get into your oil , im not gonna say thats not your issue ,but is usually fairly obvious if the cooler is goin bad enough to get in oil , have seen some front cover issues but not many
i dont do the whole oil analysis stuff , because i think that it makes most people paranoid they have major issues when they most of the time dont , but how much coolant does it say it has , alot or is it very minimal