How common is it for Taiwanese actors to star in PR China series and movies?

Jerry Yan currently play at Cdrama.  So many minor Taiwanese actors play at Cdrama as supporting character. So I think it is common. 

Also there is no reason to not play at Cdrama. Audience number is huge and pay is high. Even Liu Yifei and Jing Tian that already had Hollywood career go back playing in Cdrama.