Thanks for the info.
I was tossing up between transferring from CitiRewards -> AsiaMiles or MR -> AsiaMiles. MR has the benefit of there being a "known" transfer time whereas I haven't been able to get any feedback re CitiRewards (official time is "28 days", but I think they say that for all programs - and my experience with KrisFlyer, Qantas, etc, has been much faster), but on the flipside I've got a lot of CitiRewards points and would rather keep my MR points for other redemptions given how flexible they are.
In the end I decided to risk it on CitiRewards and requested the transfer this arvo... hopefully it doesn't come back and bite me!!