That sounds good Rafal. Care to code it? The structure would start with a hitvolume poking just above ground level and slowly rise to full height. Perhaps it should be at full height at 1/3 completion (to match the animation) but that's only about 12 spent on a windgen.
The aimpoint has to be moved such that it is just below the top of the hitvolume for the cases in which the final location is outside the hitvolume. This also needs to be integrated with gadgets and LUS which mess with a unit's hitvolume.
It should be possible to make a structure unable to decloak by moving it's center deep below the ground. The fake terraunit for terraforming uses this method.
I'd probably get around to coding this in a few months because it will take a bit of dedicated effort.