Alright, here’s a “radical redux” idea:
Re-contextualize the senate stuff to be about the Black Zero event instead of Africa. Several edits have done this before. But then, move the entire Senate subplot to sooner in the movie, and push everything else back.
Black Zero flashback, the Wallace stuff, all of Lex and the Senator’s interactions, and a heavily edited version of the Africa scene that’s basically just Clark saving Lois on some adventure, all happens before Superman goes to appear before the capitol and the bomb goes off. Oh, and a little bit of Lois investigating her bullet from Africa, like getting a flight to DC from Perry and sending it to the lab.
During the bombing, Superman helps victims and looks sad at Lois, but don’t show him in the fire or fleeing the scene. Edit out any scenes with Mercy in the capitol. Lois tries to console Superman over his failure to see the bomb in an edited version of their hotel scene (he doesn’t say he wasn’t looking, obviously). Oh yeah… and remove implications that Lex was the one responsible, like the piss jar. Wallace should seem like the actual bomber, making a violent statement on Superman’s inability to save people.
After that, all the rest of the movie that’s still able to happen, happens, but now with new and somewhat more logical context. Lex only begins getting into Zod’s ship and importing kryptonite now that the person who was stopping him happens to be dead. Bruce only begins violently hunting for Lex’s kryptonite after being impacting by Wallace’s actions (Alfred’s “turns good men cruel” line takes a dark new context, huh?). Superman keeps trying to be Superman, occasionally saving people and mostly focusing on the violent turn the Batman has recently taken, but he’s very depressed the whole time and is having an existential crisis, which is actually understandable now given his failure at the capitol. And Lois is still investigating the bullet after learning that it’s a Lexcorp metal, which of course ultimately results in the big reveal and her solving the mystery that Lex was actually behind everything all along. And, as an incredibly minor “bonus,” Diana Prince can make her first appearance in Gotham after the events in DC have already occurred; Diana lived in DC in WW84, so perhaps the incredibly loose chronological audience interpretation could be that Lex swiped her photo while he was there and she has now followed him back.