Rattlebox,
I have dwelled on whether to or not to prune/pinch out seedlings myself.
With the majority started about 4yrs. ago now, there are many that stayed shorter with many lateral branches and others that grew taller. I believe that they are going to grow naturally
In the way that there genetic make up dictates (short and chubby or taller), whether from same seed pod or not.
I have done a fair amount of pinching at an early stage if I felt that they where getting taller and I was trying to keep more compact. I had so many seedlings that I felt a bit of experimentation could not hurt. The one thing I have noticed is that as they where pinched at an early stage. The pinched/pruned site is almost negletable to date.
I, of course would prefer that they grew nice and compact without human intervention.
Big thing to remember is to always where surgical gloves and wash knife afterwards, as sap from the Adeniums is toxic.
Thought I should mention that I did not prune because my seedlings where etiolated from lack of sunlight, just naturally wanting to grow vertically instead of gaining girth and absent of lateral branch formation.
Rick