I'd rather we never see David's death. We go back to making Alien movies again. At some point in a future film, one of the teams that lands on LV-426 or some other planet can run across the "mutilated remains" of an unknown synthetic. After realizing it is not a human, since it has not completely rotted, the audience can infer the manner of death from the severe damage done to the body. And, the destroyed surrounding and remains of whatever cave, ship, or structure the body was found in can relate the details of what went wrong, and what David ultimately was up to after Covenant.
Think of it like Walters death, or the destroyed hallways of Hadley's Hope when the marines arrived. We could tell where the last stand was made, where the fighting had taken place, and it was far more eerie than showing the events themselves. We never saw what happened to Walter, but I think he had his head cut off (kind of like david) and was left to sit there alone for eternity. Maybe David will come back for him once he's "learned". But the fact that we don't really know what happened, makes it more frightening, sad, and effective.
I'd rather leave David and his horrible experiments and fate to the histories. Floating off into the dark unknown, like the space version of the titanic, is the best conclusion I could imagine for him. Maybe they could pull an Alien 3 Bishop move, and temporarily reactivate a part of him, and see something horrible he was doing, or see his death. I say use him for an Easter egg, and move on.