The thing with some initial hybrid formats is that the ones that work eventually become formats in their own right. The old "Recuerdo" pozole format comes to mind.
The "pozole" format was actually an undiscovered mainstream format.
In Mexico, any station that wants to optimize sales targets upper and middle income listeners, because there is much less ad revenue spent reaching lower-middle, low and ultra-low income levels (C-, D and E socioeconomic levels in their media world).
A, B and C+ listeners don't regularly listen to what we call "regional Mexican music" and what is correctly called "grupera"" in México. In fact, it is socially acceptable to demean that type of music if you want to demonstrate that you are of a better class.
But in the US, the vast majority of first generation immigrants from Mexico came from D and E income levels "back home" and so they have a liking for regional Mexican as well as for the artists they saw on TV on shows like "Siempre En Domingo" and on all-Spanish contemporary hit music stations.
A research project in LA in 2000 showed that the bulk of over-35 first generation Mexican immigrants liked pop, regional and grupera music. Bukis, Vicente and Juan Gabriel if you know the artists.
So Recuerdo was born as an adult hits station, using the breadth of "Jack" and the variety of pop and regional. It was just hidden previously due to the way Mexican radio is programmed to income levels, not to age groups.
I managed the research and named Amalia González as PD. She assembled the music and we tested it and I put together the mechanics of the categories, rotations and acceptable segues and blends.