Really? Maybe you should name a few, because after asking my sister's boyfriend who flies into/out of HKG on a monthly basis (though from Shanghai and not anywhere in Japan) if you don't have HK residence you can only show the necessary arrival/departure stamps or have the qualifying FF program to get the Frequent Visitor status. Anything else would involve "opening back doors", which isn't an impossibility, I guess... Also, he's an HK resident, so he already gets access to all e-channels without having to go through all this and subsequently may not be paying full attention to non-resident methods for obtaining e-channel access, though it matches with what's on the Immigration Department website. Nothing other than those two methods if you're not an HK resident (well, you went and e-mailed the HKTDC; most people won't even think of doing that).