I have a 10 yr (M) Visa issued in the USA, I've used it 3 times in the last 5 mth

The company I work for in the USA has a partner in Shanghai. I've been traveling and working for them for 1 week, every 4-6 weeks. Currently, I live in Thailand so it's not a super long flight. I'm a USA citizen, by the way.

Now, they want me to relocate to Shanghai which means I need a (Z) and have to do a bunch of paperwork, medical exams and pay fee's etc. I don't want to go through all of that... Why? I don't know if this company is going to stay in business. They're having a lot of financial problems. I don't want to get set up in Shanghai in a apartment, utilities, phone, taxes and private health insurance etc. And then they go out of business and I'm stuck with a "apartment lease" I can't afford to pay. Bad and dangerous situation!!

Could I keep my (M) Visa and go to Shanghai and stay for the 60 days allowed each time, and then do a boarder run to exit the country. Then come back and stay another 60 days, and then do it all over again? As I mentioned I live in Thailand right now. People here do boarder runs "all the time" and it's not a problem. The question is- is it exceptable on a China (M) ?