I did it in Aug 2019, but sorry to say I can't find the paperwork

I remember following the instructions in the post below though, and quite sure I had to go down to SCB branch to get the share transfer form.
https://forums.hardwarezone.com.sg/...ny-things-club-4866757-499.html#post110302760
Attempted to transfer IWDA from SCB to IBKR in Apr 2020.
Was subsequently told by both SCB and IBKR that the transfer is not possible, because SCB can only perform the transfer using local UK CREST, whereas IBKR has a mandate to receive all iShares holdings through Euroclear only. To be exact, IBKR can receive GBP holdings using CREST, but iShares holdings cannot be performed through CREST.
Since SCB cannot use anything other than CREST, and IBKR cannot receive iShares through any other means other than Euroclear, the transaction was declined. The transaction was done using the Share Transfer form located on SC Trading Online, and also put in a request to receive positions on IBKR through International Asset Transfer (similar to the instructions in the quote above).
Since there have been successful transfers reported (Sep 2017, Aug 2019 as far as I'm aware), it sounds like something may have changed in settlement instructions for SCB or IBKR.
@those who succeeded - any chance you could assist to ask how the transfer was made, and whether it was using CREST or Euroclear? Also if this method can still be continued moving forward?
@Shiny and other friendly advisors here - caveat is that starting out with SCB and then transferring to IBKR may no longer be feasible.