I think they want to take it all the way up to the Supreme Court, no half-measures.
So they want to lose big and take our Liberty with them? Thanks a lot?
Better to at least establish through practice the right to distribute these technical plans to Americans with the least possible amount of red tape (a EULA checkbox before download that says you are a US Citizen or Resident and will not export to citizens of other countries) and then fight for reasonable regulations on export. They should do this now, on their website, right now if they are at all serious about this issue.
The courts are not going to accept a prior restraint argument if there is not even the slightest care or check on whether the files are being requested by foreign sources.
Encryption was hard enough and technically web browsers and other software with encryption could still be export controlled, but actual weapon plans and schematics are going to be a bridge too far. And at least with encryption software there was a letter of the law attempt to comply export regulations. The court is going to have little appetite to go into the degree of lethality of the weapons in question to establish some higher threshold for exporting weapon plans abroad.
This case is overreach with all risk with the only hope being that the courts rule against this case more narrowly to allow them to fall back on the methods and procedures for export control that I suggest be applied.
Instead of establishing a file sharing community where amateur gunsmiths were actually sharing plans and making improvements to weapon designs and making some responsible efforts to make sure that people posing as foreign nationals at a time of ISIS weren't given weapon designs, this entire effort has been an immature attempt to put the cart before the horse that has been destructive of efforts to maintain 2nd amendment rights.
Somebody else please set up a marketplace for pistol, rifle and shotgun designs and schematics, put up the EULA to keep out foreign nationals and let's give them attention and praise for actually furthering the science, art and engineering of pistol, shotgun, and rifle design. And if that new website is sent some cease and desist letters threatening them, then let's support them, because then at least we can possibly win and protect the essence of the 2nd amendment which protects Americans right to keep and bear arms, not the rights of people in other countries.