Qin Qiong did not participate in the changes of Xuanwu Gate. First of all, it can be said that it is related to his position. Although he worked for Li Shimin, the king of Qin, his heart was not entirely in Li Shimin. It can be said that he was loyal to the current emperor Tang Gaozu, so when Li Shimin planned the change of Xuanwu Gate, he naturally wouldn't take the initiative to participate.
Secondly, this is also related to Qin Qiong's conservative character. In Qin Qiong's subconscious, he would think it was too risky. If it succeeds, it's either success or death. Plus Li Shimin's men were not short of generals from the front at that time, so instead of taking the lead, it was better to wait and see the situation in the back, and then choose to take sides when the situation was clear.
In addition, this is also because Li is not incompetent. Although Li's ability to lead troops is inferior, his ability to govern the country is definitely not below. Then Qin Qiong saw this, so he didn't have the heart to participate in the change of Xuanwu Gate, because he didn't want to be the executioner to kill the prince, but with his ability at that time, it was impossible to change Li Shimin's decision, so he chose silence and didn't participate.