Uncle Sam will blow these Chipmunks to smithereens should they get any funny ideas. US politicians are evil and policymakers pretty deluded, but their military is still the most capable fighting machine on the face of this planet by a large margin. If there is a military engagement, China will be brought down to its knees and Nukes would be imminent. Hope they don't 'miscalculate' because 'it is a policy doomed to fail' (in their propaganda mouthpiece parlances).
Forget US involvement, Chinese will find it difficult to take Taiwan even if Taiwan fights alone.
There are very few landing zones on Taiwan coast which Taiwan has fortified for decades.
Landing operations are difficult already.
Unless there's a complete collapse of Taiwanese armed forces or an extremely faulty use of tactics, Chinese will lose too much.
The question is if CCP believes Taiwan is worth lakhs of soldiers and trillions of dollars.
Only viable strategy is to eliminate Taiwan navy and focus on an embargo to whittle down Taiwanese resistance in a multi month campaign.