Also sorry for the late reply, the thread went under in me having a finals thingy to take care of, ill check this stuff out ASAP!
Edit: I ran the mdx ruby script against both, mdx from MGS1 and ZoE1 that i extracted with my tools, and in both cases i got a more or less usable midifile! Looks like ill have to read up on how to midi so i can add samples to these to see, what kind of sequence the MDX actually contain (there still are MDX-like sequences inside the EFX files).