That is not to say it can't be done.
Use separate balustrades for each edge.
Offset you balustrade as you have done - say 200mm
Off set the support rails as well (I have not done that in this image).
Use the double end (corner) post option so that the very corner post is not there and set the distance to the same as your offset (200mm).
In plan position the rails so the offset posts overlap.
The only problem you might have (depending on what you need) is the rails.
It seems they can't be separate lengths.
So the support rails for the balusters will be correct but if you want more rails back on the post you won't get these to work (at least I couldn't).
You do have the top rail which you will have to reduce the end by 200mm and you could also use a handrail and play with its position and length.
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