I would be interested to know how your .svg file was created. I use several software applications for handling graphic design. Even at relatively low magnifications, the file looks to be odd. Here is a .jpeg snapshot of the file in one particularly capable vector image editor which I use. The screenshot is at a magnification of just over 1500% and any vector image should hold up to scrutiny at 8 or 10,000% magnification. Your file follows:
The red rings denote areas of the file which may prove difficult to parse and it is these areas which may contribute to very long loading times for this particular file. It loaded in my image editor instantly but took a very long time in Luban. I would possibly try and run the file through an image editing suite with well established and known credentials.
I have also an .svg file of a guilloche pattern that I examined at 8000% magnification and did not see any of the artifacts that are very clear in the file you which you so kindly provided and I sectioned for illustrating the point. Anyway, these are just some thoughts which may assist you in future. I have not yet tried Luban 3.7.0 so I can only go by what I am seeing in 3.6.1, which did not manage to load your file in a timely manner.