It wouldn't be all too special, you might end up with an animal that looks more like the regular Nosy Be as appose to the true blue Nosy Be.
Jim at chameleon company, here in the USA produced on accident crosses. Ambanja X Faly, I am thinking they will turn out looking cool but they are not so different that they'll create something crazy weird looking.
An Ankaramy X Nosy Mitsio or Ankaramy X true blue Nosy Be would be something to see!
I'm against crossing but this is just me.