I still standby this Ultimate Edition of the TC though, and it really tought me a lot. It was the first extended cut I did that I really dug deep to find new stuff. Was fun to work on, on and off for a few years, and it met my original goal.
To be honest, your Ultimate Cut of the originally released JL is my favorite cut of all. I do not like the new outter shell of Steppenwolf of the Snyder Cut, nor do I like the 4:3 aspect ratio that it was presented in. Makes the film entirely unenjoyable for me.
As much as I would like to, it just looks so drastically different ot the rest of the film. It's in scope while JL is 1.85:1, different lighting, mood, SFX, framing, etc. It doesn't fit the aesthetics as much as I would like it to.
With that being said, I'd like to make a small argument as to why the items you mention might not matter as much. For starters, the film starts off with what's basically a cell phone interview. Doesn't get much more jarring on framing than that. Next, with the cut scene added immediately after it, at least for the last few frames, you could use a black wipe transition because after that, in the cut of the film (which would normally be after the Superman interview), the screen goes black for a moment or so before the "Warmer Brothers Presents" verbaige comes up on a black screen, thus having a transisition between those 2 different framing aspect ratios that's not even as jarring as the original transition (cell phone interview -> rest of film).
With respect to lighting, the Cut Scene is darker I admit because it's a Batman Scene (I keep wondering why solo Batman scenes HAVE to be so dark in the live action DC Universe... UGH. They should lighten up just a bit so one can actually SEE what's on screen...), but the next scenes are also a little dark as well due to it being Batman at night. But you're also talking indoors clandestine vs outdoor chase. If needed, couldn't you lighten the cut scene just a bit to make it a little brighter?
Please keep in mind I'm not trying to hound you to include it. It just dawned on me a short bit ago when I watched Suicide Squad after having just watched your JL cut for about the 4th time and thought it would be a perfect addition and noticed that nobody had touched on it in this thread.
Like I said, your cut AS IS is by far my favorite. I want to thank you again for the production you put into it and making it available. I do appreciate it.