Transferring from OA to SA in CPF

[sgd]

I remember there was an article in the newspaper some years ago, this guy in his 20's transfer money from OA to SA he said the 4% interest is only paid for upto 250k. I can't find anywhere in cpf faq which still says this or whether this has changed or not.

but consider transfer to SA is irreversible you cannot take it out until retirement at 55yo and after that only excess of the minimum sum combined of oa+sa.