Well the key to this is not actually Pelosi but the actions of the DPP. As others have said, Pelosi could stand up and say she recognises Taiwanese Independence, but it doesn't actually count for much, because she is only the Speaker of Congress; a senior Congresswoman. Yes there is much symbol;ism but little of substance in her visit.
If the DPP start to say things along that ilk then that is a very different matter and that will illicit a much more robust response.
China will, I am sure, see this as a deliberate disregarding of their red lines and so the Chinese response is likely to be in kind.
The kind of thing they can do is to formally disavow any recognition of US Sanctions on third party countries
Or they might give formal recognition to the Lughansk or Donetsk Peoples Republics.
This is an exercise which is mainly symbolic and designed to make Beijing lose face. It can reciprocate to make the US and DPP lose face.
Military Exercises which do not recognise Taiwanese territorial borders and limits is a low cost way to do this, as the Taiwanese military is highly unlikely to respond, nor will the US.
If something stronger was needed, the PLA simply need to overwhelm and occupy a few of the smaller ROC controlled Islands just off the Fujianese coast. Again this would expose the impotence of Taipei and Washington at very little cost or risk.
The best way to deal with Pelosi is to respond in a way which blights her triumph and leaves vast numbers of those she purports to care about cursing her name and the fact she was ever born. Pelosi seems like a woman in search of a legacy and so to poison the one she is currently seeking to create, seems the most effective rebuttal.