There are 3 essential and very helpful changes in this pull request:
The imported models are named after the file name. This permits an easier identification when importing more than one model at a time
The export is extended with the ability to export objects as a batch. Just like the feature while exporting STL files.
there was a Scaling issue when the length unit was set to mm and the scaling factor to 0.001. Only with these settings the measurements are correct. If one has imported an STL and a 3mf at the same time one of those was out of scale. With this fix both have the correct measurements
There are 3 essential and very helpful changes in this pull request: