Beside ASIC miner profitability. Did some technical (chip enigneer) party did scope all the techs on the miners from Bitmain. I am bid paranode is a producer manufacture chips whit unwanted funtions, like share a bid of the hasrate to the producer.
Its pretty common that producers make on purpose backdoors for there on use. Recently like INTEL had back doors pointed out as manufacture failures (yhe right). Microsoft put updates to cover those back doors.
my concern is that bitmain is kept on a close eye what they are doing. My doom senario is that the have a backdoor to optain the hash rate at a trigger and overcome the 51% of the network haspower. Okay i am a bit paranode in nature, but think its good the point it out