Then Steve Rogers' criticism about Stark never being the one to make the sacrifice move (The Avengers) still holds true in the present day, which means he's learned nothing since becoming Iron Man. "Not asking for this" becomes self-protective BS the second someone decides he's going to make decisions / take actions on behalf of others, which is what a superhero does. For that reason, Stark should finally be pressed into learning what "signing up" means by being the one to die. For once, he would not think he's going to tech/trick his way out of a situation, and face a threat, knowing he has no chance. That would finally add some drama to the entire Infinity War story, and serve as a strong bookend to 10 years of MCU films with the end of the character who launched the series--and finally learning what sacrifice of self means.
Except he's put himself in that position several times, New York and the nuke being the single most prominent example but far from isolated. Every time he confronts some powerful being intent on killing him he's making the decision to risk exactly that sacrifice.