Hi Ralf, thanks very much, I'm glad that MoI is working well for you!

One thing that I would currently suggest for working more easily with large files is to adjust the display mesh density setting.

By default the display mesh is set to be rather dense which makes for a very smooth looking display but also takes up more memory per object.

If you have a lot of surfaces you can reduce memory consumption by a significant amount by changing the setting to get a coarser mesh.

To do this, go to Options / View / Meshing parameters, and set "Mesh angle" to 25 degrees, and uncheck "Add detail to inflections".

That will cause the display to look slightly more rough, but the memory consumption and polygon density of the display will reduce by a lot to make the heavy file handle a lot better.

I'm hoping to make this process somewhat more automatic in the future but for now you need to adjust those settings manually to reduce memory use for heavy files.

- Michael