The only logical response is to raid US ships supplying to Taiwan
That could still trigger a direct US military response. Until Washington recognises Beijing’s hegemony in Asia, the US Navy maintains the upper hand on the high seas (excluding the First Island Chain). In other words, the US Navy still has the edge in seizing Chinese commercial vessels on the high seas so long it occurs outside the range of possible nearby PLA naval assets. And of course, since China has virtually only two overseas bases, it would be impossible for the PLA Navy escort all of its commercial vessels. Unless China could somehow increase the number of overseas bases through Harry Potter’s magic wand, this will likely be a weakness for years to come.
A smarter retaliation may be to trigger some kinds of armoury explosion (or malware-induced industrial accident at TSMC or UMC) on Taiwan through sabotage that contains US-made weapons. It sends a message that Beijing would retaliate but not directly against the US (deep state gets the message without Orange feeling insulted).
The PRC could very well turn Taiwan into a punching bag the way North Korea is doing against South Korea. There is a famous NK joke that states, “whoever commits aggression against North Korea, North Korea always strike South Korea.” Maybe China can do the same to Taiwan (and Japan plus Philippines). Whoever conducts covert ops or other acts of aggression against China, China would do the same to Taiwan, especially DPP-affiliated organisations. Such retaliations could range from simple theft of trade secrets to assassinations and sabotage of critical infrastructures on the Island.