You guys are both mischaracterizing Hawaii's policy, which I believe is the source of your disagreement. They designed it very cleverly to avoid the type of complications you're talking about.
Even setting boosters aside...
Hawaii's policy is not: You must be vaccinated to enter the state.
Hawaii's policy is: You must quarantine for 10 days when you enter the state. If you're vaccinated, you are exempt from the quarantine requirement.
Thus, it's not a vax mandate (and wouldn't be a booster mandate). It's a quarantine mandate with a vaccination carve-out.