David,
my cobra just expired but my last attempt to get a hybrid approved (fusion at L5/S1 with Charite at L4/5) was denied. I had Pacificare which was bought out by UHC. When I pressed, they conceeded that they would approve the fusion at L5/S1 but would not approve the adr at L4/5, and did indicate that they would approve at 2 level fusion (since I pointed out that the injury to my L4/5 is the same as to L5/S1).
I am now on a state health plan for people whose Cobra has been exhausted. Was hoping to try a 2 level pro disc claim ...until I read what you wrote about no off label use being allowed
May have to try the hybrid approach with pro disc with my new ins. Good luck to us!