Unless you have a reliable escalating life annuity in sufficient or better amount. Then all other wealth is instantly transferrable and bequeathable. I also illustrated upthread how you can self-convert the CPF LIFE Standard Plan to deliver a
guaranteed residual -- and in fact an escalating residual starting by age 80 or less -- if you simply plow back all excess amounts above the CPF LIFE Basic Plan monthly payout into your CPF Retirement Account. So if you care about delivering a non-zero residual to a nominee, there you go, there's your answer.
Only one of us is fixated on the residual.

But OK, if a non-zero residual is what you want to guarantee, no problem! Pick the CPF LIFE Standard Plan but consume only the CPF LIFE Basic Plan payout amount. Plow all dollars above the CPF LIFE Basic Plan payout amount back into your CPF Retirement Account. Mission accomplished.