Hi @klnichol - Thanks for reaching out. It's exciting to hear that you have a trip to Hawaii planned for this summer!
The hiking boots vs trail runners question is one that is talked about a lot here in the community. It often boils down to it being a personal decision, often based on which shoes' benefits are most important to you and the logistics involved (like having to pack them).
We wanted to share this thread titled Hiking Shoes vs Trail Runners with you, as it is currently quite active among other community members. A wide range of trail conditions are discussed, including many that are similar to what can be found in Hawaii, so you might find some suggestions that help you with your question.
For another look at the topic, our Expert Advice article Hiking Boots vs Trail Runners: The Great Debate is filled with information comparing the two.
If you're keen to share, we'd love to hear what you end up deciding to bring on your trip.
Hopefully this helps!