I just included a short presentation of what I call "CoreIDX" on the Duet3d forum. It is my conversion of a CoreXY to an IDEX. It is similar to the Markforge style implementation of an IDEX system but my 2 lower belts/pulleys maintain their original positions as in a CoreXY. I just separate the X carriage into two and tie one of the belts to each new carriage, along with a Y drive motor andby Gilly3D - CoreXY Machines