I honestly do not know the answer to that question. I don't know if there is, and what the %, a require co-partnership with a mainland factory.
I do know that in Guangdong/Guangzhou province, one of the main factory city areas for Taiwan manufacturers, there are certain huge city areas that are basically Taiwanese cities.
And the concept of Taiwan management who work there are quite well-known for having "Little Wives", that is marrying mainland women to be their wife while they are over there. Although, its losing acceptance among the Taiwan wives...gradually...but it is not as accepted as it was even 5 years ago. And there are a lot of Taiwanese wives whose husbands work on the mainland. Divorce is not as big a 'loss of face' as it used to be here.