May I ask about what’s your idea of preserving privacy with self-hosting a website that searches for specific terms from a presumably fixed IP, where by 1/3-1/4 chance it can be attributed to you?
EDIT: It was located in a german street light 20km away from any of the users. Just to get the geolocation question out of the way.
It was more of an experiment than anything else there will be a talk about it and other FreiFunk (Open Mesh Network in Germany) related stuff at the next virtual CCC congress.
Note: since the version 1.0, searx stops sending request for 1 day when a CAPTCHA is detected which might help a little.
(I'm really interested by the results of your experiment)