“I suppose we could simply formally recognize Taiwan if the PRC gets violent with HK.”
And then what?
...And then realise that that declaration carries the same weight and measure as a formal declaration of war against Mainland China, and be prepared to reap the whirlwind.
Unless the west is indeed prepared for WWIII, Taiwan’s reclamation by Mainland China is pretty much a foregone conclusion at this point, and the ChiComs know it.