Yeah but honestly, redrawing patrol lines so that we patrol more territory and expel them when they try to patrol it is pretty good actually. It is curtailing their control of the seas and expanding ours. We're not going to start killing their fishermen (unless they get really unruly and try to fight, which I've never heard of) as that would be counter-productive to a foe you're ultimately trying to assimilate so short of going to war to end the Taiwan question, salami slicing the nautical territory they dare patrol is about as good as it gets. It's just a question of how much of it we get.
It’s honestly insane how many opinions China has as its escalation dominance is ridiculous. If it really wants to make a point, it can capture the ship responsible for the murders and put the crew on trial in China for murder.
But that might be going a little too far for Beijing’s tastes, but the main point is that the threat of it doing so is real and will play on the minds of Taiwan patrols and their crews.
Also, the current response isn’t merely more patrols that ignore each other and do their own things.
China will now actively counter and block attempts by Taiwan to patrol those waters. Taiwan’s patrol boats can expect highly aggressive blocking manoeuvres from their mainland counterparts almost to the point of baiting them to fire the first shot. At a minimum, they can expect highly aggressive blocking actions up and including water cannons and bumping, maybe even outright rammings if they annoy the Chinese crews sufficiently.
A strong, maybe even excessive response is demanded, because China cannot and will not allow Taiwan to normalise the murder of Chinese civilians in Chinese waters. A weak response will only embolden more similar acts and may end up forcing Beijing’s hand on AR if Taiwan goes too far and Chinese public sentiment gets too inflamed.