If China actually catches up and surpasses the West/TSMC in fab technology and production, I think they'd have a better option, which is simply flooding the world market with high-end chips and obliterating the Taiwanese economy. Eventually, joining an economically dominant China might become more palatable, or a necessity.

China is building all kinds of suggestive tech including invasion barge piers to land heavy stuff quickly once a beachhead has been established http://www.hisutton.com/Chinese-Invasion-Barge-OSINT.html

The track record says China will probably just buy Taiwan.

If you hate invasions so much, you should probably focus your energies on Venezuela. Looks like Trump might start a war for Christmas.

Peaceful democratic transition is also on the table when KMT wins back the presidency next.

I know mass media keeps pounding this "eventual scenario" (manufacturing consent and all). Maybe it will happen, but the Chinese think on longer timelines than the ADHD West and are probably banking on A). Out-attriting, B). Out-innovating. If both happen, we might find ourselves with a situation where Taiwan voluntarily wants to align closer with China as the West flails.