You did see a spike in silver, but that may be merely episodic and may fade.
Do you have a potassium free coolant installed?
If you do, you may be seeing the start of a head gasket failure in this hard used engine.
If you don't, then unless you see potassium, you don't have coolant getting into the oil.
Dare to be different and try M1 0W-40.
It might reduce some of the wear metals that you're seeing.
I know that the turbo Subie crowd loves T6 and that the Subie cult in general disdains any flavor of M1, but the Euro formula is an exceptionally good oil at about the same cost per quart as the Rotella.
T6 claims none of the certs for highly tuned gas and gas turbo applications that M1 0W-40 does and the Germans who developed most of these standards weren't stupid, they just wanted a set of standards that would enable their stronger engines to live under hard use.