Hi Daniele,
in exports like this you need to consider different things. In the mentioned workflow, there is no OBJ export, but I suppose different format (it is a good way to export FBX with undistorted images). Also you need to consider different coordinate system orientations between RealityCapture and Blender).
So, for proper OBJ import to Blender you need to set transformation like:
Also, as the orientation is different, the values won’t be on the same position.
Blender:
RealityCapture:
You can also notice the slight differences for angles. I suppose this is because using distorted images and undistorted results.
So in your workflow, thy to use the rotation values from Blender for undistorted images and use undistorted images in your reprojections.