I've been working on a little search wrapper. It allows using features like DuckDuckGo's bangs and Kagi's snaps with any engine you choose.
For example, you can search "cheese", and it'll show you results for cheese on Google. If you search "!b cheese", it'll search "cheese" but on Bing instead. "@yt !b cheese" will search "site:youtube.com cheese" on Bing.
I built it mainly so I wouldn't blow through my 100 Kagi trial searches quite so quickly.