Given the size of the modules, I wasn't able to achieve full UHD resolution, which requires 12 by 6 modules. Instead, my setup tops out at 11 by 5, which gives me 3,520px by 1,800px. In short, I lose 160px on the left/right and 180px at the top/bottom. At first, I was concerned, but after photoshopping some movie stills, I think I'll be alright. Note as a purist, I prefer keeping a 1:1 pixel mapping for the video signal.
For example, here is the Hateful 8, which is shot in glorious 2.76 AR.
Avengers Endgame has a 2.39 AR, which is also very decent.
Once the AR drops below 2.0, I start losing details on all four sides, as as in this still frame from the IMAX presentation of Interstellar.
Scaling down to the max width of 3,520px certainly keeps a very pleasant presentation. However, I don't know how much I will notice the scaling by the Radiance Pro and if it will distract me more than the loss of image area. Some testing will be needed, but it's certainly a preset I will have on hand.
Similarly, for some widescreen/fullscreen movies, I may need to scale to the max height of 1,800px.