You'll have something if there is a sizeable FBAR market, and you can demonstrate that for whatever reason they will:
1) Produce lower losses than normal
2) Accept higher premiums
If you can demonstrate both you will make lots of money.
You don't need to just prove that FBARS have a better claims history than native borns. #2 is actually more important.
You've found that as a FBAR you are charged higher rates than you deem reasonable. If this is the case, chances are that there are many more FBARS who feel as you do.
Gathering them all together in an affinity group that at least acknowledges that they are getting screwed
but promises to try and fight for them will give you clout with insurance companies.
This won't be a short term project however.
You should also think about what, if any, peculiar consideration or requirements FBARS have concerning insurance.
Obviously having customer reps who speak a variety of foreign languages will be necessary.
My bet is that FBARS feel that they are neglected segment of our society and will easily be attracted to a production source that can connect with them on a personal level.