I didn't find it in the list of the "Photo Gallery". I have several seedlings taken in Autumn 2018. It's apparently a fast grower. November 2018, "Arboretum des Barres" : Seedlings, Feb. 2021 and Oct. 2021 :
Seedling are looking nice! Don't know how to get pure ssp. aidzuense unless there are no other tataricum ssp around. You'll have to wait and see how the more mature leaves look. (I can't recall if young leaves are slightly lobed, but that would certainly be typical).