This bpost provides simple binary framework. It is applicable to my and wife’s cpf withdrawals after 55.

Green_portion channel is irreversible, so use it as a last resort.

— channel: from OA

Right after RA creation, “excess” amount flows into OA. Any OA balance is 100% withdrawable any time, including subsequent salary contributions. OA becomes something like a bank account. No restriction like ‘SA top-up amount is not withdrawable’.

— channel: from the green portion of cpfRA. See [21]cpfRA for liquid parking@4% – dTanbinvest