I am aware of the difference between IRV and approval voting. I am pointing out that there are examples in the wild of non-exhaustive systems being exploited. A

I am aware of the difference between IRV and approval voting. I am pointing out that there are examples in the wild of non-exhaustive systems being exploited. Approval is non-exhaustive by design, but even in a system where exhaustiveness had been the norm for decades a single political party in a single election was able to substantially regress its performance.