Hi, Kamikaze. To be honest I have not checked any of the vids posted (just riffin' from memory here in betwixt other stuff in the meatworld).
"Modal interchange" to me though sounds like swapping out a minor mode for another minor mode when the root chord being played allows it (and similarily swapping out a Major mode for another Major mode when the chord allows it).
What the past few posts have been about is literally changing keys via the harmony. As in the actual chords of the harmony are breaking the key whereas just swapping out one mode for another may break the "melody" key while soloing but the overall harmony/chord progression remains intact.
To go back to the 12 bar blues I, IV, V analogy...
You can play various modes over top of those chords because they are not complex enough to cause "clashing".
What Voda is describing is like if we took that I, IV, V harmony/chord progression and turned the perfect IV into something entirely different... like a flatted diminished II or whatever.
In his paradigm it's the natural F that screws it all up JUST for a second (or you could "imply" that mode for the whole bar with the bass line, or another guit, or piano or orchestral stuff... lots of ways to approach it).
Your basic triads for Major and minor chords allow you to swap out modes rather easily. Once you start adding other notes (such as the 7th) you start limiting your modal options. Also the chord progression/harmony can bugger you up too... as in your mode may sound good over one chord in the progression but once you move to the others it ruins the modal vibe you established because you didn't take into account the overall progression.
uhm... okay I'm not sure I'm being useful with this post but ya... doin' shtuff.
Will clarify when I can.
Cheers!