If I understand your usage of phase 'Now...not so much" to mean at some past point China feared moving on Taiwan because of perceived strength of US military, but China no longer afraid to have it's way with Taiwan because US Military has been weakened.

If China senses weak US military, do the limit aggression to just Taiwan?

You never attacked the sheep for fear of the sheepdog. When the sheepdog grows weak do you attack the sheep, or go finish off the dog first.