Opening stairs and moving duct

Going down the stairs, it feels like I'm going to hit my head on the first joist, so I want to move it back and make it a bit higher.  Here's what it was before I started

So I cut it away and shifted the main one 16" back.  I'll be putting in a 2x4 to extend it out so it meets so the wall will meet up with the edge of the window frame, but I'm not doing this until I get over to that area with the floor leveling since I want it to be as high up as possible.

Before I tore everything apart in the upstairs, this bedroom had it's vent in the floor, a foot or two away from the wall.  Since I'm moving the wall back, it'll be even worse than it was, so I got some ducting to shift it into the wall like the rest of the rooms.  This was way more of a pain than I thought it would be...