Sorry, to say, but Kagi has no interest in separating the AI stuff from their plans or providing a kill switch. Previous thread about this was locked with a response that amounted to "we may do something about this in the future, but we're not doing that now, just don't use the features".
Supposedly your money won't go directly to using AI if you just don't use it, you'd pay separately on a per-token basis. Though it's certainly going into R&D and dev time to implement and support such features, so whether that's okay is up to you.
I'm personaly sticking around for the search and cautiously observing how things progress.
