zero - There's a free Berklee College of Music course taught by none other than Gary Burton which goes into this to some extent, perhaps not to the depth that you are seeking, but at least it addresses the modes and some of the 'extensions' you are referring to and how to look for what would make sense in an improvisation sense. I will re-take the class again, because I think I absorbed about 10% of the material first time around.
Here's the listing for the class:
https://www.coursera.org/course/improvisationNext session opens October 13. It's a tough course, I'll just warn you up front. There's quite a bit of homework involving analysing existing songs and scores for appropriate modes and so forth. Don't be discouraged by the first week's assignment - it's rather difficult. What can help is to look up other versions of the first week's assignment on YouTube - to get a sense for the melody of the original song.
The course almost takes the opposite approach of your question - in that it's teaching improvisation techniques based on chords and key signature, and looking for what scales work best in a situation when you aren't told "oh here, you would use mixolydian then switch to dorian in the next measure, etc."
But the 'extensions' and the appropriate improvisation mode scale, coupled with the melody and how it's interacting with leading chord notes are absolutely interrelated. I think you would find many of your answers by taking the class. Oh, did I mention that it's free and the instructor is Gary Burton?