Which major broker allow trading Malaysia MYR/USD and Taiwan TWD/USD currencies? I looked at IB and TOS and they don't seem to have them (or do they?).
These are both non-deliverable, if I am not mistaken. I don't believe that many retail brokers offer TWD & MYR NDFs. Some Asian banks (e.g. Singaporean ones) might, though.
Try https://www.square1financial.com/ndfcontract or http://www.uob.com.sg/corporate/corporate/treasury/asian_non_deliverable_forward.html or http://www.icap.com/markets/electronic-markets/ebs/non-deliverable-forwards.aspx