OP here. I haven't abandoned the thread, but my dealer is so busy that the appointment I scheduled after my OP was weeks out (now next Monday). I sent the video of the startup over to the dealer (first post) and they said they don't hear anything abnormal. I can appreciate that they aren't going to approve an entire warranty repair based on my vid, but to say that this sounds normal doesn't seem right.
Sanity check here: is that not the tell tale cam phaser rattle in my video? Here are both vids I've taken.