Xiu Jie also thought highly of Shen Tai, and believed that Chaoyan would decide to keep him. Therefore, he had helped Shen Tai right from the beginning by addressing him as Master, rather than Lord. In this way, his real identity was not exposed, and things would be less complicated. Otherwise, there would have been more trouble for Shen Tai.
Shen Tai's brother and his wife were definitely greedy people. If they knew that Xinlin Clinic was supported by someone in the imperial family, neither Shen Tai nor they would have a peaceful life.
Also, that possibility might have caused Chaoyan to give up on Shen Tai as well.
Xiu Jie was, honestly speaking, a very careful man who had taken a lot of things into consideration.
Chaoyan had told him that she was going to train her own staff. And he believed that Chaoyan had made a correct choice in picking the right candidates.