"To qualify for the tax incentives, firms must invest at least $100,000 in the territory, buy products such as office supplies and computers in the U.S.V.I., contribute to area charities and hire at least 10 people, 80 percent of whom must be natives of the islands.
Company owners must live in the U.S.V.I. for at least half of the year, under federal requirements. They have to undergo five examinations a year by the Economic Development Authority.
The IRS published a notice saying the statute of limitations restricting the agency from examining more than three years of tax returns doesn't apply for those newly claiming U.S.V.I. residency. That allows the IRS to inspect tax returns going back decades.
The IRS also drafted a new form for island residents it says is needed to prove valid residency. The form requires those who stop filing tax returns with the IRS in order to file them in the U.S.V.I. to list where their immediate family lives, where their cars are registered and where they hold driver's licenses. "
The Bloomberg article (my emphasis added) is from '07, but I doubt much has changed. In other words, it's a serious pain in the ass, and as you suggested, only worthwhile if you're making well into the 7 figures.
Though I'd still make the argument that in such an instance, buying citizenship in St Kitts or Dominica is the better option. Why go through all that extra legwork (hiring employees, audits, tests, etc), all with the possibility of failing any one of them (or the laws change, or the IRS merely "revises its guidance") and risk receiving no tax benefit whatsoever, just to save your passport?