I wouldn't patronize a business specifically because it caters to the unvaxxed. I'm not really into reciprocating negatively. I'd prefer the businesses I patronize to treat vaxxed and unvaxxed the same.
Screw the businesses that are enforcing the yellow star system.
The moment we try to reciprocate in-kind, we continue the division. It isn't the vaxxed's fault that businesses are enforcing the yellow stars, they just believed the propaganda. So, punishing them for being vaxxed just pushes them away. We want them on our side even if we might disagree with their decision.