Sorry, I wasn't as clear in my original post.

At the bottom of the settings page you can generate a "bookmarklet" that includes the config options in your URL. So https://duckduckgo.com/ becomes https://duckduckgo.com/?kae=t if I want the Terminal color scheme. And this works without cookies. And this applies for all possible settings.

Interestingly I set my home page to a string that should disable all the AI features and I still got summaries sometimes so not sure if that's a bug, user error, or hostile UI. In either case, something like you suggest with https://noai.duckduckgo.com/?kae=t&etc=... should give you the best of both worlds.