Stefan,

make sure that Cinelerravcan open and save MXF.

In June of this year, Andrew added 6 video MXF formats for rendering/saves and 2 audio.  You can currently read in MXF videos as I just downloaded and tested sample_1280x720_surfing_with_audio.mxf.

MatN,
Just sounding out if there is interest in supporting these xml formats as import/export.
If someone has an interest in providing them, we can add them !