To give a little back to the community, I would like to share my macro with you: I used to perform quite a lot FEM analyses with FreeCAD, however, I prefer to export the results to VTK and then to visualise them using ParaView, which has a lot more options for that. Unfortunately, FreeCAD can only export one VTK file at a time, so I came up with a little macro that I use for transient analyses. The macro exports the FEM results and also writes a VTU file in the same folder. The VTU file can be simply opened in ParaView, and that way you directly have the transient results with the correct timestamps.