here is why hybridization is hard/rare ( in my opinion)
the plants will pollinate themselves readily,
pretty much as soon as they open,
its hard to isolate the flowers,
the flowers are numerous, and small,
its hard to cross pollinate them,
and
the seeds take a long time to fruit.
other than that, it should be possible in some cases...
I'm sure quite a few hybrids exist out there already...but here is what gets me..
they call the red jabo a hybird (precoe, hibrida, same thing) but the seeds are all true to type with very little variation. I have my doubts it's a true hybird, maybe it could be a distinct species, or a variant of M. cauliflora.
I haven't dedicated too much effort to breeding, and hybridizing species, but I believe it's a worthwhile effort.