You are releasing your 28nm designs when you already have a 16nm chip out in the wild. Economically this is useless. If you wanted a decentralized Bitcoin Blockchain you would've release this last year, not now.
16nm chip will work on 28nm boards.
"So from 1 UART connection we're able to service up to 1700 hash chips (over 20TH/s with our 28nm chip and even more with the 16nm). 16nm will work in a very similar way."