I just tried this and it worked in seconds. My KBank account received the amount as soon as I pressed confirm on my email. I got the email within minutes of setting up the transfer on the Bitkub web site and used Google 2fa.
I decided to transfer all my funds out of Bitkub since they are asking for KYC documents again or threatening to stop trading later in month December, I already went through that 2 years ago, and now the section for foreigners for KYC is blocked. I left 2THB in the Bitkub account but doubt I will use it again.