Hi @Jeremias !
You are right. The existing documentation about MIDI options is really poor and incomplete and it should be improved.
FYI, many of this options are also available from the UI’s admin menu, what you could find more comfortable for testing and trying to understand them.
Anyway, you can ask whatever you want here. Most of times you will get an accurate answer, so perhaps you could improve the documentation by forcing us to explain, one by one, each option 
BTW, did you already vote in the contest poll?
The best!