Personally I would not bother with Raffia on a tree that small, No need as until the wood lignifies they are very supple, and i would put up into a larger diameter pot to start to develop radial root spread from day one.
I have tried without raffia before, and seriously damaged the tree, so it is more of a precaution.
The tree in the video and the trees in the other post will be for very small shohin or mame bonsai, so I am trying to slowly develop them, hence the small pot.