Boldly acting in front of Ji Xuanjing would indeed offend this Second Prince, but Han Zheng no longer cared.
This Second Prince didn't even inquire about his demands before forcefully repaying a favor, which seemed generous but was actually subtly taking Sheng Tian'an's side.
In reality, for Ji Xuanjing, Sheng Tian'an was indeed more useful than Han Zheng.
Not to mention the strength of both sides, Han Zheng was one of the Thirteen Guards directly under the Grand Commander, making his identity sensitive. Even if someone owed him a favor, it wouldn't be appropriate to command Han Zheng to do some sensitive things.
On the other hand, Sheng Tian'an was the Tower Master of Black Feather Building, which had countless bandits and villains in the thirteen branches that could be commanded by Sheng Tian'an, making him most suitable for dirty work.