Ok so the .chan comes out of Terragen via the Camera export as in your video.
This is how the chan looks:
1001 -108667 -292496 3.40204e+006 4.51821 -79.3968 -94 37.8493
Orientations I actually get:
83.890 3.932 -90.737
As far as I see, the numbers match my Terragen scene perfectly so it's all as I expect and as per your video, but then bringing it into Maya with terraMan results in the orientation being wrong, but the position and FOV come in perfectly. The steps are following your video.
I've kept rotate order as xyz.