Because the K & N change makes for what is essentially a new algo, it's not possible to have one port that supports "different equihashs" at the same time (unless the pool has special software to change from a to b). One miner that autochanged algos based on a given pool's switch would have to coordinate with that given pool. That's just not how miners work, unless they, or some overlay app, are proprietary to that pool (like nicehash).