Not so sure about that, are SearXNG immeadiately identifiable as such, if not it just looks like any other search. Also does the evil eye actuaully care about edge cases like self hosted SearXNG? Still, might be nice to rotate the exit node...
ETA I also keep google off for default searches, and use it by bang only when other things fail, a rare occurrence.
You're quite right about the Pi 5 power efficiency, an Alder Lake N100 / i3 will smoke it in ops / watt given the right board, but the context was 'a several year old used desktop' which the Pi will handily beat.