please come tl;dr at me about Shen Wei

I need to figure out stuff about Ye Zun, and [spoilers], but also stuff about Shen Wei! Since having other people say things about the thing is in general a productive way for me to acquire thoughts, I now invite your opinions on Shen Wei and secrecy. He's trying to tell Zhao Yunlan the absolute minimum to protect him and also the timeline, yes, but in a divergent scenario where he was unavoidably associated with Zhao Yunlan, how much would he tell? What do you think is the core of the (over)protectiveness and secrecy? What is the root of his nondisclosure?