My guess is ... they are actually selling everything they get to big customers.
I do not believe they are selling any to big customers (or at least those big customers are not mining with them yet).
Why do I believe that? Network-wide, the DASH X11 hashrate has not been climbing, it's actually down a bit this week from peak. If they were shipping miners and big customers were mining with them, one would expect to see that in the hashrate.
BTW: This same argument holds true to debunk the suggestion that Baikal themselves were keeping the hardware and mining with it.
mining4bacon