It wouldn't make much sense to invest in their own 28nm chips, the NRE for quick tape-out/fast chip produce is around 5M.

Eventually because of the insane competition in this marketplace come January, you'll start to see the price of mining rigs hit very low prices <$5 and then the next batch will be <$2 and by the time ice.drill would have had their own chips, the price per GH will be so low ESPECIALLY for bulk wholesale buyers that the cost savings in developing their own chip wouldn't be worth the time/effort/cost.