No to the running whilst being de-Iced question.
In so far as What parts were replaced during service was never disclosed to me other than it was a major service and a lot of bits and pieces were replaced.
I don't believe a 20% reduction in efficiency to be weather related, it didn't happen last year.
The significant point of this event was that before service I returned 48mpg, after service 40mpg, it wasn't even cold when the car was returned after service but I still achieved only 40mpg.
As I implied in my initial posting, I suspect I have an argument with KIA service on my hands and my posting was fishing for ammunition to use in that battle, as I know very little about 21st century cars. I am from the simple days of the mid 20th century, and all has changed, sometimes for the worse.