I am mining with a GAWminers black widow, which is just a rebranded zeusminer, and can solo just fine with the zencontroller they include. I don't know why I am feeling the need to point this out, as it just confirms what you already know which is that it's not the hardware at fault. Just wish I knew what was hashing away underneath that zenOS skin so I could help.
its highly likely a modded cgminer that actually does work, if i remember rightly CG doesnt cut the system off after 60 secs without a share, but i may try and nab a rip of that zen software and see what its doing, if its just a pi/beagle i can make one easily