A Singapore Citizen or PR withdraws over a ten-year window starting at the statutory retirement age, with 50 % of each withdrawal taxable at resident rates. Because Singapore's brackets start at 0 % on the first S$20,000, a retiree with little other income can often withdraw a substantial sum paying almost nothing.
A foreigner faces a structurally different event. The 5 % early-withdrawal penalty is waived only if you are not a Citizen or PR on the withdrawal date and for the ten years before it, the account has been open ten years or more, and you take one single full withdrawal — a partial withdrawal forfeits the waiver entirely. 50 % remains taxable, at the non-resident rate.
So the Citizen optimises a slow drawdown across brackets; the departing expat faces one irreversible decision with a ten-year clock attached. No tool models the second case — and the higher foreigner contribution cap of S$35,700 (against S$15,300 for Citizens and PRs) means there is usually more at stake.