Is the Simitai section still closed now? If it is, should we do the jinshanling trek to Simitai?

According to the information I got from the internet, Simatai section is probably open at the beginning of April or May. It's possible that you treck from Jinshanling to Simatai (around 10.5 kilometers) but tourists are not allowed to visit the Simatai section. So I am afraid that you can't do that. It's very dangerous. You might get hurt or lost if you don't have local guide.