I have read through the entire thread about ORA Mandarins. While I don't doubt your feeding issues, that thread has a lot of 'fluff' from people who don't actually own them. Is your Spotted Mandarin not accepting food at all? I have a Wild Caught Spotted in my Prop Tank that refuses to accept frozen or pellets. With that being said, he has stayed alive and healthy for almost six months living off of the live copepods and other plankton that thrive in the system.
In my opinion, the best thing you can do is to supply the aquarium with an ample amount of pods. I got a ball of Chaetomorpha algae from TMZ that was beaming with life- maybe if you ask, he might be able to help you out. Another option would be to try and soak the pellets and/or frozen food in a garlic supplement. It always helps when I have a fish that refuses to eat. JMO