That’s all nice and fine, but has your mechanic checked the state of the banjo bolt filter for the turbo yet? If he hasn’t, then your new turbo is going to fail in short order.
Here, read these two threads from Subaru forums on the topic:
Don’t think that just because your engine has had oil changes every 3500 miles means that your filter is clean. It takes 30 minutes to do the job, if it hasn’t been done already.
BC.