Probably the author used the Past Progressive for he wanted to emphasize the continuity of the actions. If I were the author, I'd have used the Past Simple.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
I would say that these became mixed conditionals through the substitution of were for had been, which is a common substitution, especially in everyday conversation. I would say that the 'original' thoughts and meanings were:
If you