Zathura, which is a lot like MuPDF. Press d to toggle the dual page view.
Edit: My bad, just read the part where you said “the option to adjust which 2 pages are displayed”. The dual page view in Zathura will show 2 adjacent pages. When I’ve needed to do that I’ve just opened two Zathura windows. Especially with a tiling WM it’s practically the same feature.