It's federal law -- it doesn't matter what Hawaii wants.
What they "say" you can't do, and what really can be done are totally different. There are many laws here that are facially invalid, this would most likely be one of them.
When the Federal government says officers with xxx can carry while traveling across state lines it will fall within Federal power and the states can't claim 10th Amendment rights to prohibit that. We really need to take a step back from what is allowed, to what is legitimately legal under the laws of the land.
For example,
The City and County of Honolulu is trying to tell me that all notaries require a stamp. However, provisions in the United States Code say that certain signatures, when accompanied by name and title of office, are considered prima facie evidence that the signature is genuine and valid. Because the 'man' here says it's no good -- doesn't mean that it is legally not.