Honestly every diesel vw i have had has oil in the cooler pipes...this treg is my 3rd. Its normal...if you are not seeing the need to add oil in between changes you have nothing to worry about....there is no abnormal turbo noises and it works as intended i would worry less and drive more....Ive asked my tuner...my vw tech buddies they all say oil in the charge lines is normal...it is a byproduct of oil cooled turbos.
I will be changing my turbo out for a new bigger one in a month or 2 i can take pictures of mine too but im 99.9% sure it has oil in the lines as every tdi ive seen does