See if this is of interest to you:
I am developing a pointcloud Python/C++ script to process pointclouds. It can create elevation, contour and slope maps and show a colored map of the deviation of points from the plane of a wall or floor in a building for use with BIM flow. It only needs the pointcloud XYZ data and can generate the surface normals from that. It is fast, creating a deviation plot for a 10Mpts cloud in 3 sec. This includes reading the cloud from a file. Currently it supports primarily XYZ data files. You would need to use CloudCompare to convert e57 scans to XYZ format before reading in the cloud. Another forum user told me it took Revit hours to create normals and deviation map so this could offer a significant improvement if it takes that long for your scans.
Let me know if this is of interest to you. If so then I would need you to send me some scans (can be e57 format) to test that it works properly for your case. Then I could provide you training in its installation and use. Currently only Windows is supported.
Regards,
Terry.