Didn't live on Maui, but I did live on Oahu and visited Maui a few times.
Maui has two things working against it when considering gifted education options:
1) Thin population
2) Pidgin as a first language - this is why Hawaiian schools rate so poorly
Services for gifted children tend to increase wherever there are more of them, but both of these things will have the opposite effect.
My experiences with nativism were isolated, but enough to show that it's definitely a thing.
In general, I'd say you're right to be concerned about your children's educational environment, but there are a lot of other factors to consider in making a leap like this, and there can be some amazing benefits. There are some great opportunities there to learn outside the classroom. Think dormant volcano, tide pools, coral reefs.
