Small inaccuracy
(I glanced at the previous posts, I hope it wasn't mentioned yet)
At the very beginning of the video in the original post, radar altitude shows 0. In DCS it shows 5, which I assume is the actual distance between the sensor and the ground. From the footage it appears that the offset due to landing gear height is taken into account...
Easy fix I suppose. Just add an offset to the displayed Ralt. However, from an engineering standpoint, this offset should disappear when the landing gear is raised. Can't argue that from the HUD footage though...
DCS 1.5.3 btw