I’d definitely keep the Superman vs the League fight. It doesn’t matter for the story, but it’s one of the biggest draws for superhero team-ups: seeing “who-would-beat-who” and “how do these two things interact” sort of playground-discussion comic book fan stuff. Flash realizing Superman can see and keep up with him was easily the most fun part of the theatrical cut and is still one of the best moments in the Snyder cut.

If there’s anything to bring over from the theatrical version, the one thing I think absolutely should be brought over is Whedon’s version of the scene where Flash gives Wonder Woman her sword in the tunnel fight. In the theatrical cut, there is a parademon right behind Diana as she’s falling, about to catch her, and because Flash taps her sword into her hand she is then able to quickly spin around in mid-air and slice the demon. It’s a fun and exciting bit of action showing the team work together. In Snyder’s version, however, the parademon is inexplicably missing from that shot, so Flash’s sword-tap accomplishes nothing (if Diana didn’t catch the sword, she’d just pick it up of the ground when she landed) except for knocking the wind out of himself when he reaches the bottom.

The only problem here is that the theatrical is 16:9 while Snyder’s is 4:3, but my ideal version of this movie would be edited to be 16:9 anyway.