If you want to keep privacy, don't choose the zap but instead send a regular lightning tip to the user. Zap for public view, regular lightning tip for privacy :)
Discussion
I'm not sure of the benefits of npub-linked zaps. Not sure it promotes intended behaviors and quite some risk it promotes virtue signalling.
IMO, I think the benefits is in some cases people can kindly encourage more positive behavior because mainly most of the times notes that got a lot zap have an interesting signal. Instead of simply cheap likes, there are economic value bounds so high quality post will be more appreciated. People can see easily that in public and make them think "oh this notes got many zaps, why?"