When I formulate recepies...
Melenoiden is to me like a darker munich. I use 7% to 10% in my vienna recepie (which made mini best of show in the final round of NHC...so I must be doing something right
I kind of think of it as a 20L Munich. Most of the recipes that I use Melenoiden in, also have Munich, and I have swapped out portions of Munich with Melenoiden over time to get a richer toasier flavor. In other words, I think all the recepies I use Melenoiden in, started life without it, but with Munich... and I have used Melenoiden to tweak the flavor profile.
I also use Aromatic in place of Melenoiden when I cannot find Melenoiden. (That used to be the case quite often, but in the past couple years has not). I use Aromatic and Melenoiden interchangeably. The differences between the two at the quantities I use are not detetctable to me, but may be to some.
In my mind, Aromatic and Melenoien are products made by different maltsters to fill the same role in the malt market... a means to add flavors similar to decoction, without the extra three hours to the brew day.