First let me state that this is the best image viewer in VR for 3D photos as all other media viewers and I own all of them cannot handle really high resolution photos.
But the app seems to always pick the wrong aspect ratio while viewing 3D photos.
The worst is selecting all the available formats manually also gives bad results. The only way is to select Full SBS matching and the photo looks perfect.
Unfortunately, the automatic detection of full SBS does not seem to work.
I think this should be auto selected for any 3D photo.