That's some cool stuff!
If you're angling towards a post-rock audience (yes - unsolicited advice

), I'd suggest having the drummer reign in his Jazz-Metal improv tendencies, and lay off the cymbals by about 80% of his current work rate.
Even though there is a great overall God Speed... vibe, there is a disconnect between the drums, and everything else currently (it may be post-rock, but the rock aspect is still important).
Have the drummer listen to as many of the hundreds of bands John McEntire has drummed for, as well as bands like Dianogah, the Dylan Group, and of course Slint (that bludgeoning drum riff on "good morning captain" is the major motif, that everything else adorns).
That track you posted, could really slam, with a more spare drumming style, and the drums more down tempo (at his current tempo, a less improvisational style would take you in to Space-Rock territory, so he needs to play at a tempo that locks the drums with the rest of you, to bring it in to Post-Rock land).
Of course, I'm only making these suggestions on the pretext that you are striving to tailor your music towards the Post-Rock genre...
If on the other hand, you're simpy exposing your music to a Post-Rock audience : don't change a thing. What you're doing is great!