CPF OA to SA transfer or MS Top Up to SA?

Reader:
"I would like to make transfer from OA to SA so I did a check with CPF. Assuming that I reach the full retirement sum at age 55, they mentioned that I cannot withdraw cash top up to SA and its accrued interest but I am allowed to withdraw the OA to SA funds transfer and its accrued interest. I am confused however. My initial understanding is if my combined sum in OA and SA exceeds the full retirement sum, I am allowed to withdraw the access funds. If that is the case, whether it is cash top to SA or OA transfer to SA, should not make any difference. If you could clarify on this issue, I will be greatly grateful. Thank you."

AK:
"MS Top Up is a cash top up meant to help us with funding our retirement. It is an additional input and not part of the of the annual contribution limit (mandatory + volutary).The OA to SA transfer is money that is already in your CPF account.

"The OA money is from mandatory contributions and voluntary contributions (if any). These are made within the annual contribution limit and not in addition to the limit.The CPF is meant to help every member with retirement adequacy.

"Whether we choose to do OA to SA transfer or MS Top Up will depend on our circumstances. Whatever those circumstances might be, the MS (or the FRS) will go to our CPF-RA at age 55 and cannot be withdrawn (unless we choose the BRS by pledging a property) until age 65 at the earliest in the form of an annuity (i.e. CPF Life).

"Unless our CPF savings are made up entirely of cash through MS Top Ups to the SA, it is unlikely that we won't have a more meaningful lump sum withdrawal at age 55 if we should exceed the prevailing MS (FRS) significantly by then."

Related post:
1. Almost 55 and worried about CPF.
2. Did CPF Top Ups but denied lump sum payment.