I'm not aware of Chinese authorities getting quite that draconian (yet) at the normal border entry points in Beijing, Shanghai, etc. However, I think it's still worth following the general advice that if you have sensitive data on your devices, leave them at home and use a burner phone/laptop + restore from the cloud later.
Quite different from the rest of China.
Hire a car+driver? Mysteriously cancelled at the last minute. Pressure on any translaters/fixers you may have. Drive somewhere that isn't the hotel? Find that there's an accident and you can't pass that way. Shops that close, constant tailing from security and police, general harassment, and nobody will talk to you because they believe they'll disappear.