Red overwrought with orange

Working on a piece for my Memories of You show to be played by a trio led by Chris Cowie, one of my former students and the flautist with my ensemble. The trio are alto flute, clarinet and cello and I'm calling it Red overwrought with orange after Ezra Pound's Envoi. The alto flute is really the soloist and the two other instruments provide a frame (amber?).
The clarinet and cello glissando through a whole octave (in opposite directions) over the course of seven minutes (see below - instruments are at notated pitch). Need to double-check that this is actually realistic on the clarinet but hopefully it should be quite effective. There should be as few breaths and bow-changes as possible, and the dynamic should be as quiet as possible throughout.


The alto flute part is built up of fragments and the flautist has choices about the order in which they are played. The part is constrained by the limits of the framing pitches as much as possible (though the three parts are not coordinated).
I'm also going to write six solos (rhythmic or timbre specified but not pitches) for each of the clarinet and the cello. These can be applied at any time. There will also be three duos for the clarinet and cello that can also be applied at any point (but these must be coordinated between the two players). There is also one trio moment (this moment has only one possibility for the alto flute).

I'd like to prepare different frames for different versions of the piece: two electronics and one orchestral. The first electronics part is made up of sine waves, and the second from recorded chromatic drones on bass flute.