There's another option: use CPF LIFE for what it's best designed to do: guarantee monthly payouts for life. Then, since you have that guarantee, be more aggressive with the rest of your wealth. In particular,
give it away! Don't wait for yourself to expire. You've got a grandkid accepted to Yale? Pay the damn tuition bill, now.
A bigger high quality sovereign guaranteed income stream for life, particularly of the escalating variety, gives you
huge financial freedom, and you can and should be generous with that freedom -- to yourself and/or your loved ones.
Yeah, I know, many people don't understand what I'm trying to explain. I live in hope some of you will understand.
I rather doubt the SRS outlet will be viable at age 70+. Once you start withdrawing from a SRS account, which you're allowed to do as early as age 62 (for those who have or open SRS accounts by June 30, 2022), it's a one-way ticket. And you probably don't want your SRS account to end with a fat balance when you end, because that tax outcome isn't great.
If you shield with the right fund selection (a low volatility, highly "onshore," high quality Singapore dollar denominated bond fund) then -2% is highly improbable. But you're exactly right that even hellaciously terrible timing is still going to end up with a good result.
The BHS is fixed from age 65, so from then on you can only refill when there are withdrawals from MA. And since MA is earning 4.0% interest you probably want to avoid MA withdrawals if you can, unless there's some income tax relief at stake.
You can add funds to your RA every time the ERS is raised -- for the rest of your life if you wish. RA earns at least 4.0% interest, and that high interest earning basis/foundation feeds into your current or future CPF LIFE income stream.
Once you've exhausted Voluntary Contributions to MA, RA top ups, and "all three account" Voluntary Contributions -- and among family members -- OA repayment then becomes the next most attractive option within the CPF universe. OA repayment is at the bottom of the attractiveness list, but it might still be comparatively attractive if you get to that point....
....But I don't think so. By that point I'd probably be handing the money to someone who has a longer time horizon than I do, to build/grow truly dynastic wealth via prudent long-term investments. And thus I've come full circle to make the same basic point again.