Just a little note, mostly for that I remember it better in the future 😉 . Like Virtools, Unity's coordinate-system is Y-Up, unlike 3ds max where it's Z-Up.The Virtools exporter does all the conversion for you under the hood (except for Characters).
Looks like for Unity you need to pay attention. Currently my level in Unity is rotated 180 degrees around the up-axis, compared to the 3ds max scene. I realized that a bit late … Anyways, for characters, car and the like one can do the following to get the same Z-Axis alignment as forward orientation in both applications:
Go into pivot-edit mode ("Affect Pivot Only" in the Hierarchy of the Command Panel) and rotate the pivot so that Z-Axis (blue) points forward, the Y-Axis points upwards and the X-Axis points to the side (left side). Then in the FBX export dialog choose "Z-Up" under "Axis Conversion". This way, it's very close to the Unity system – only the X axis is mirrored.
Thank you too much, Dominique !