Everything you said about shady and unreliable vendors in the bitcoin mining space is likely true, but that doesn't change the fact that repeatedly making promises without putting anything of substance behind them is cheap talk, and is very different from making a binding and substantial commitment to the customer.
But they did put something of substance behind them. They shipped some SP10 faster than advertised by a couple of days. How can they prove themselves regarding the SP30 if they will receive chips early in July?
"Something of substance" meaning a commitment that binds them to the outcome. Talk is cheap. If they say "it will ship on time and on spec," that's one thing. If they say, "you can get a refund if it doesn't ship on time and on spec," I'm more included to believe it will ship on time and on spec. I don't really want the refund, I just want to know they are willing to put their money where their mouth is on the promised ship date and specs.