I have not had any contact with BOI about accepting a Roth IRA balance for the $100,000 substitute for a "Bank" balance in lieu of a foreign or Thai health insurance policy and do not plan on raising the issue with them until my recertification in three-years. I continue to maintain a Thai health insurance policy as fallback, but given the nature of Thai insurance companies, the 25% discount for a 40K ThB deductible and a 3-year no claim discount keep the policy affordable (to me) so it can serve as a major medical policy.
As mentioned before, my Roth statements have a three-year look back chart on the first page and every December statement shows there have been no distributions or contributions in that calendar year under "Retirement Contribution and Distribution Summary" or something similar demonstrating that increases and decreases in the balance are the result of market movement and not me drawing down my balance, and as a retiree, I cannot contribute to it, so it is a lump of money that earns returns (or absorbs losses) under my brokerages 'private client' advisor scheme. I am fortunate in that between my Social Security benefit (direct deposited here) and my government pension paid into my U.S. checking account, I have not needed to withdraw from my Roth IRA
The Roth serves as the principal asset I will be leaving to my wife if I pre-decease her or split between two educational institutions (a daycare center I taught at in the 1970s and the graduate school I attended in the 1990s) should she pre-decease me.