Ken, in my post above I showed "arabicums" that I need to transplant to begin root training.
Your obesums above are perfectly fine and doing well so there is no need to transplant at this time. I would suggest, however, that the terminal apex be nipped so as to make the tree branch out. More branches, more flowers, plus the caudex will grow fat quicker. When the caudex nearly touches the pot rim, then it's time to transplant.
As you may know, seeds rarely take on all the characteristics of the mother plant of obesums. They have been cross cultivated with other subspecies. My obesums have different leaf forms, colors and textures. And the caudexes have different colors and textures also; I had/have some that were pinkish then turned into a green, grey, or brown color. These variations are perfectly normal for obesums. Allow the lower leaves to fall off on their own...there is no need to remove.
Note: The information given here is based on my own experiences with obesums.
