For what it's worth, it's only within the last couple of decades (or so) that Adenium socotranum (which our database treats as a subspecies of obesum) has become relatively widely available in cultivation, at least in this hemisphere (though it remains extremely uncommon, expensive and hard to find).
I have passed on opportunities to play with that plant because I think the climate here would probably not be a good fit. Not enough warmth. Both during summer (no surprise there) and during winter (even despite our lack of frost). As it is my arabicum does not fully leaf out most years, so I don't think I should skate any further closer to the edge of possibility, especially for something that will take a long time and has reasonable odds of just up and dying some winter because it rained at the wrong time.
According to the Pachyforms book, socotranum does not flower (or branch) until 3-5 years old and is "probably the least cold tolerant of the genus" (apparently requiring warm winter temps not less than 60°F; he recommends overwintering them inside on heat mats). No branching until puberty. Leaf drop when subjected to transplant/temperature/drought stress. High casualty rate. Intermediate growth rate (for an Adenium). I have read elsewhere to expect extended periods of dormancy, but maybe not in the tropics.
