I am in the midst of watching the "behind the scenes" documentary on Netflix about the making of ST- First Shadow.

Interesting tidbits I have learned thus far:

(a) Young Bob Newby seems to work in a radio station.

(b) the script underwent several MAJOR revisions during the production process.

(c) A major reveal was cut from the script because the Duffers wanted it to be kept to be a reveal during for ST5.