Hi Cameradan,
As an owner of a original SteadiCam®, I think I like to answer that.
The movements that you can do with a SteadiCam®, can be quite different for each take. It needs a short analysis what you have and what your target is. Otherwise, any general answer is without greater value.
The idea here is to replace parts of the scene that are far away. Will say, the amount of noticeable parallax must be negligible. Elements close to the camera, as long as they are not just flat, will not work here.
The area what needs to be replaced is small in the tutorial. If you get a stable camera tracking, it seems most-likely possible to replace larger areas. Again, this might be limited by the overall distance that the camera moves.
If the parts that needs replacement are surround by objects which are not moving, chances are greater that it works.
Well, the quality of the SteadiCam® operator count in as well. A SteadiCam® is nothing that produces magically a stable image by itself. The average time to get feature film quality results is found to be one year. It is easy to introduce additional motions into the image, based on bad handling, or no training. I exclude a longer discussion about that here.
The ProjectionMan is only a management tool, nothing else, it doesn’t track the position not gives you the practical camera data. It does not handle Rolling Shutter artifacts not motion blur from small bumps.
A Steadicam® shot, if well executed, is in the family of a crane or dolly shot. Which might answer the question as well.
All the best
Sassi