I´m just no so sure that this tree´s initial phase can be regarded as a "Mallsai" as we have seen so many times.
The fact that this tree has more potential than the average, S-shaped trees does not mean it is NOT a mallsai. It is.
A mallsai is: "purchased from garden centres, shopping malls and chain stores", according to:
bonsai4me.com/Basics/Basicsdevelopingmallsai.htm
Do note that this page describes a transition from mallsai to bonsai - with a similar starter and great end-result, same as Marco's.
Actually, such trees are sold by bonsai traders as well (they do need to make a living...).
See:
lodderbonsai.nl/en/about-us
Some pictures I made there:
There's a mixture of trees there - the typical, S-shaped ones, ofher mass-produced ones (but not an S-shape) and real bonsai.
You can find material like marco's tree there (which will be a long search... there are loads of trees there) for a relatively low price. But it's going to take 2 decades to create good bonsai out of it.