I think the biggest issue is that you've shown you're willing to modify traffic for license control. If you'd simply released commercial support for $500/mo/instance I'd have gladly paid for it in my products and think many others would have too. Showing such obtrusive forms of DRM makes me not want to ever use any of your software again. I've spent the past couple of hours migrating from Caddy to nginx and I've contacted them about buying support. I guess the silver lining was the nginx was was easy to migrate to.