Here comes my update
Working Day 0: Submitted both forms to SCB branch
Working Day 4: CDP called me to verify my transfer instruction over the phone (NRIC, Mailing Address, Share name, and number of Shares). I also took the chance to ask about the charges involved. The officer replied that an undisclosed amount will be billed to SCB (who may or may not pass on the cost to me).
Working Day 5: My CDP account was debited of the shares i am transferring
Working Day 9: SCB credited me with the transferred shares on their online trading platform
(If SCB passes on the CDP charges to me, i will update again)