Another Avengers: Infinity War tidbit coming from Christopher Markus and Stephen McFeely panel at San Diego Comic-Con as the pair revealed that Smart Hulk almost first showed in the third act during the Wakanda fight and burst out of the Hulkbuster to kick the ass of Cull Obsidian.
— HN Entertainment @ SDCC (@HNEsocial) July 19, 2019
The character came out of the blue in Avengers: Endgame which was a little jarring.
Personally, I think I would have liked to have seen that as the Bruce Banner/Hulkbuster sequences in Avengers: Infinity War had the sketchiest visual effects work in the entire film. I dug Cull as well but could have had a little more to do at the end there, it’s a shame that the scene was cut.