He pitched well at basically every step of the minor leagues. First exposure to big leagues over a full season was very good.
Last year, in 40 innings his peripherals outside of his HR/FB rate were still very good, and regression would be expected out of that 22% number because it is not in line with anything he has done in his career. The 40 innings with the BoSox is the number to me that skews the data, not the rest of his work. Red Sox bought him at his highest peak, and sold him at his lowest. They didn't do that one right IMO.