My short film starts in 1.37, and ends in 2:1. The overall project file is 16:9 (4K), and i've added black bars within that container to create the correct aspect ratios.
The way I see it, I have two options for creating a 4K DCP (1.85):
Option 1) Center my 4k 16:9 export within the 4k 1.85 DCP. Easy peasy. The 1.37 part of the film is pillarboxed as expected. No problem. But the ending (which is 2:1) is letterboxed AND pillarboxed when it doesn’t really need to be. The advantage here is that the 4k video is presented in its native resolution.
Option 2) Export my project as 4k 1.85:1 so it fills the entire DCP. The 1.37 bit will be pillarboxed the same as in option 1. The advantage here is that the 2:1 section will only be letterboxed.
I think I prefer option 1, as it doesn't require me to blow up the 2:1 section to fit the 1.85 width, which I worry will degrade quality. But is option 1, for lack of a better term... weird? Will this look odd in the theater, with the last 5 mins of the film floating inside a pillarbox/letterbox combo? Or is this pretty standard?
That's the essence of my question. Is option 1 weird / offputting / strange looking in a theater? Sadly I don't have a theater to try this out in, hence why I'm asking here

I attached a diagram of the two options for you visual thinkers. Any advice is much appreciated!