Take a listen to their podcast they talked about the more suppressors they sell on this run they can invest in more machines to make more suppressors faster. I think thats likely the reason they can't use the silencershop platform as it was intended. The products they are making are different/awesome enough that people are willing to do it, so more power to them. To be clear I am not rooting against them and hope the can is successful enough that I can buy one on silencershop one day 
The rokstok drop they just did was a very similar 90 day lead time deal. They would have to front the money to stocky's otherwise. Maybe someday it will be that you can just order one and it shows up in two days like all the other stuff I have bought from them 
That just sounds like typical business practice...using revenue from product sales to purchase more equipment to meet demand. Though, from what I can tell, that second printer purchase isn't going to be necessary haha. Seems like a lot of folks are waiting for the larger OD/ID version and/or further testing in either the TBAC Summit or by Pew.
I'm with you on the Rokstok debacle. Hindsight is 20/20 and all, but yeah never should have been a pre-order.