Not a requirement but more like a pre-requisite before you even come for the interview.
Go to Kowloon HC and do ALL the MILF there! IF your didi can "salute" all these MILFs with no lag time.. you pass the pre-req. If your didi only stand to attention to SYTs, consider a career change.
Why? Becoz your clients are all gonna look like the MILFs there except now you are servicing them instead of them doing you.