Nice work Jérôme you have done well with them
I can see why these plants are so expensive keeping them alive at seedling size is quite difficult I only managed 2 plants and they rotted off eventually from over zealous watering.
Sadly the mother plant which was from Crug died in 2010 and now its one I do not have.
I have S.alpinia here I do not think its the same plant as this is so sloooow.
Hopefully yours will flower and seed Jérôme