in my opinion, it depends on your situation, here is a brief idea only:
1) your age
2) your risk tolerance
3) the available funds in your new MPF plan, since you mentioned the high risk portfolio, however, there might have global equity vs hong kong equity vs european equity, all of these might be defined as high risk , but as you should know the performance is totally different, and the potential gain is totally different as well
at last, even you would like to invest in a high risk portfolio, it is suggested to invest part of capital in a conversative asset as the global economy is not yet stable.
it is just my personal opinions! pls consult your profesional advisor for further details
