@GigiPlumeria and
@RobertFJameson.
Sorry that I didn't get to this sooner, but too much going on.
As the consensus above indicates, multi petaled adenium are not produced by grafting, only reproduced. They are a genetic mutation and aren't produced by mechanical manipulation. The first attached article is quite old but does indicate how one could develop their own line of multi petaled flowers from seed. Essentially you take a single flower with color, shape, size that you like and use it as the seed parent. Then take a multi petal flower that has a good shape and use it as the pollen parent. The resulting progeny (according to the article) will be ~15% multi petaled the color of the seed parent, ~50% multi petaled the color of the pollen parent and the rest single petaled. If you then cross the 15% with its multi petaled siblings or parent you can start getting large numbers of multi petals the color of the original single petaled flower. Note that this takes a while because you have to grow the plants to blooming size and sexual maturity. This is why grafting is so popular.
https://www.siamadenium.com/ar...
The second article is a study of variability/heritability in Adenium and explains why this is a good method to produce the results that commercial hybridizers (not grafters) are looking for. It's a little technical but worth reading.
https://www.researchgate.net/p...
