Requesting a review from a significantly stronger player (2k+) on behalf of my opponent (@KVM1950 who isn’t familiar with forums).
To me, White abandoned the mirror too early (granting Black a good exchange) then missed a good exchange of his own. These errors together left White with insufficient territory.
Thankyou for a very informative and well articulated review. KVM1950 appreciated it based on review comments which I hope you saw:
KVM1950: Thank you so much @Mark5000 ! Very interessengruppen and helpful comments-I learned a lot from That!
I found it very helpful too and it went some way to answering questions which I’ve had sloshing around for a while.