Yes, bud grafting. Seen this done here at home with other trees (Genus). Not tried it w Adeniums.
Definitely worth a try.
I do not like the appearance of "V" or Cleft grafts, although I have done to try my hand at it. The graft Union always is visible and does not seem to diminish over the years. I find that the Flat grafts seem to more so.
Seems that a Scion w half the caliper (diameter) of the Root stock becomes less noticeable as opposed to one close to same caliper size.
Look forward to seeing your trials.
I had cellophane tape quite wide and I tried cutting the whole roll in a narrow piece. Not! a good idea. It melted or stuck the cut edge of the roll together.
Rick