For someone with a tiny bit of experience with BGA and SMD components, getting a hash board ready would take no longer than an hour.
That is a vast oversimplification of making hash boards...
This is a very high power density application that requires special attention to the thermal properties of the boards and where the chips mount. Specifically, the need for very thick power planes and a dense pattern of thermal vias under each of the chips to pull heat away from them and transfer it to the backside heat sinks.
May I refer you to part of the results from forensics I did for AMT back in 2014 regarding why their hash boards were literally going up in flames
https://bitcointalk.org/index.php?topic=569769.msg7610684#msg7610684For s19 pro there are three hash boards and each hash board has 114 chips on it, meaning 72 chips on each size of the board.
The chips are running in parallel to one another, if the temperature on any of the chips goes above 85C (185F), the chip stops functioning.
Now even though the thermals are well managed i am sure manufacturing the PCB would rquire some specific things to be taken care of but, then again, thats where my knowledge of PCBs end and thats exactly what i need help with.
My point by the above statement was assuming that if we have a properly cloned PCB, slapping on the components isnt really too hard of a task.