1) Windows. Per the official PDF doc "SysUsername" is also a parameter for Windows installations. https://cw-downloads.eu/vectorworks/support/anleitungen/VW_Silent_Installation.pdf
2) That's good news, but I think we'll stick to our reg fix, since it also removes the pesky need to sign in with a licensed VWX account. 🙂
3) Thanks, I figured that one out by clicking through the customer portal. Would generally appreciate a "admin heads-up" in the future, maybe via link to an article in the announcement newsletter.
4) Our workaround seems to work great, so far only one user had to import the .reg manually (they repeatedly got the "please enter a serial" dialogue).