The height, from the top of the CS to the bottom of the 4inch port, is 400mm. The height from the top of the CS to the point you indicated is 330mm. If you extend this to include the flange along the side and bottom as well as the red tabs on the blast gate, the height is 355mm. You will have to leave a little room at the bottom for the door to drop down enough to swing left or right and be removed.
The depth is 350mm, but you will need room for the cable bend at the back unless you make a different hole elsewhere for the router cable, and the 25mm door pull.
The dimensions of the space in my router table are 552mm tall, 345mm wide, and 422mm deep. The flange of the CS touches the side of the opening on one side and there is about a 5mm clearance on the other side.
Below is a photo of mine before the door or drawer faces were attached. Disregard the experiment with pocket holes on the top drawer and the nibbles in the corners of the one-piece face frame.
You can see one of the two disconnects I installed in the AUKTools router cable at the lower left corner of the CS. There is another disconnect inside the CS, and this allows me to remove the router and the CS box without removing the cable to the external control.
View attachment 151281
I am very happy with the performance of the CS in my shop. Chips and fine residue will build up in the corners of the inside of the CS during long jobs, but this has not been a problem. The amount in the corners depends on what is being milled, but it is never more than a small amount. At first, I was vacuuming out the corners after each job, but now I leave it. The small accumulation over the past year seems to reached the maximum point. If Incra made the corners more rounded, I doubt there would be any accumulation.
The only time I have any annoying chips flying out are when I am cutting dados in panels. The chips at the start of the cut fly out, but once the piece is over the slotted rings in the router table, everything is sucked into the CS and to the dust collector. If I'm cutting anything else that incorporates the fence dust collection, then chips rarely make it to the floor.
I monitor the airborne dust with a Dylos air quality meter, and so far, I have run out of work before I needed a break to let the AC400 scrub the air. After over two years of use, the inside of the router motor is still clean. I didn't do a full tear down for an inspection, but had a quick look with a bore scope after an hour of milling MDF panels and didn't see any dust.