Very experienced people have told me to sell my VPN routers[0] on amazon, and I never, ever will. I own the distribution, I own the content, I own the marketing. I'm probably leaving a good chunk of revenue on the table, but overall I think it's the better longterm solution.
You may want to consider hosting your CSS locally. For whatever reason, the cdnjs CSS took around 4 seconds to load for me, during which time your site was a white page. The rest of the site loaded fine.
I say it in the FAQ, but it's just vanilla LEDE, and the mobile app uses the JSON-RPC API to communicate. The mobile app isn't open source, but the everything on the device is in UCI, cron, and /etc/openvpn.
The magic isn't in the device, it's in the flashing and configuring it for non-technical people.
But I think you are missing the point here - people who are asking the questions you are asking aren't my typical customers. It's some random guy who has never heard the word "linux".
No the op's point is that to comply with the licence you need to provide the source to customers that ask for it. She's trying to save you some potential trouble.
If his customer asks, he doesn't need to do shit if his customer doesn't ask. My recommendation would be do what the likes of Toshiba do for their TVs include in the product an offer with an email address on some hidden copyright page.
[0] https://easyvpnrouter.com/