Not sure if I ever posted about sqlay3 my BBQL emulator, but if anyone had been following the progress I've added support for reading/writing MDI files.
https://github.com/xXorAa/sQ68Lay
Adding support for these files has shown some deficiencies in my MDV knowledge, eg using Blank1_img or Blank2_img in the MDI archive results in QDOS spinning forever trying to read the MDV. I am assuming real BBQL does not do this and has some form of timeout?
The MDV code is not from qlay2 and relations, I developed it fresh based on the MiST code and Minerva notes!