Just bear in mind one point: I heard from a friend who was caught in this situation, that if you apply for this, you will never be able to get again an MPF scheme in HK even if you decide to return later... It is a one-time only, so even if some day in the future you decide to return to HK to work, you will not be granted any MPF as you have already used your only chance and redeemed it.
If your plans are that some day you may want to return to work in HK with MPF scheme available, not to redeem the earnings now, just keep them as they are. And only redeem it in the case that you are a 100% sure you will not return here to work.
Why not just leave it here? Retirement savings are important. MPF might not be the best vehicle in the world but still better than spending it.
Is there any penalty to withdrawing early, tax or otherwise? Also, I know that the MPF has fees that are quite high, but other than an immediate need of cash, why would anyone withdraw early? Wouldn't the long term gains of 30+ years eventually make up for the fees?