Just got my car back from service today. This was the 3rd time since last summer it's been at the service center for at least the mirror shaking issue (among many others), excluding the mobile service time I took the tech for an extended drive until he admitted it was still a problem after the first two attempts at "fixing it" did absolutely nothing to fix the issue.
Anyway, they finally replaced the whole mirror assembly instead of just screwing with it - pun intended - and the shaking is finally gone now, hurrah. I have the new wide-angle mirror, which I actually like as it helps me see more objects that used to be in my blind spot before (in previous non-Tesla cars I used to buy an aftermarket "aspherical" mirror to help with blind spots).
The service center did not replace the colored mirror housing, which is good since mine is wrapped in stealth PPF and I was dreading having to go back to the wrap shop again. Looking at the EPC catalog, this makes sense.
For those who are curious, here's the service item on my invoice:
View attachment 813930
Interestingly enough, the part number for the mirror assembly isn't on the EPC catalog - looks like they still have the old ones on there:
View attachment 813931