It's a known fact that Marvel Studios began development on the Infinity Saga projects years before along with other Solo MCU films. It's apparent that the filmmakers and screenwriters would have considered various versions of arcs for its characters inclusive of extra sequences and extended moments for certain narratives.
So far, extras released along with Avengers: Infinity War and Avengers: Endgame home release have revealed several 'extended' deleted scenes. Fans would have already come across such cut sequences of Smart Hulk, Tony and Morgan's soul stone interaction and more. But as the screenwriters reveal, there were many more such ideas initially considered during the early script stages, some even filmed but were left in the editing room.
Markus and McFeely recently spoke to VanityFair regarding their work with the two Marvel films and went in detail on the making process along with discussing other general topics such as life at Marvel Studios.
The Mindscape from Doctor Strange Universe was explored on big screens
The two writers offered some insight into some of the character storylines and how different they were at the early development stages. One such particular arc had an extra moment for Bruce Banner/The Hulk. Whereas, Doctor Strange also came close to exploring a location pulled right out of the character's story in Marvel comics.
"The alternate versions were sort of side roads we served for characters who had left the plot behind," Markus said. "It would be entertaining and it would be interesting and it would be cool to look at, but it would cause you to pause on the Thanos plot, and suck the air out of it. There was a sequence in the first movie where they went into the places in the Doctor Strange universe called The Mindscape and everyone faces themselves. It was great but had absolutely nothing to do with anything." McFeely further added that in The Mindscape, the Avengers would have met mirror versions of their own and with Banner fighting The Hulk.
The Hulk transformation scene was initially part of Avengers: Infinity War
"Banner meets the Hulk, I think in the arena from Ragnarok. Only one of them was getting out of there, and then that one showed up in Wakanda [in Infinity War] and he had merged. That merging that currently happens in [Endgame] in a diner, and he's eating a huge stack of pancakes? That initially happened at the end of Infinity War."
The writer even explained another deleted scene from Infinity War which showed Hulk emerges out of the Hulkbuster armor during the final fight. The scene was entirely filmed and had a different scenario built out for the character. But last-minute changes led to scrapping the entire scene and going in a different route for the character which leads to the Smark Hulk arc. Avengers: Infinity War and Endgame are both available to stream on Disney Plus.