The bitcoins they make while "test hashing" should rightfully go to the customers. Of course they never do though..
Yea, it's pretty crappy. If you're a miner already any mining they do is reducing your income, in fact— even if your not: their mining now will increase difficulty at the next retarget when (hopefully!) you'll have received your miners. Sure, a single unit isn't much, but on the principle of it they are taking from their customers by doing this.It's perfectly possible to test on a test harness or testnet, even superior: Testing on the real network will often fail to discover things like devices losing performance when blocks or coinbase transactions are large (a common firmware flaw that _several_ vendors have shipped with).
no ASIC vendor did this but at least some of them spoke about this approach!
