Hi @zethyscythe
If you launch the test using Android, iOS execution, Katalon Studio will automatically launch Appium server and don’t have this feature to allow add more arguments. You can raise this feature request at: https://github.com/katalon-studio/katalon-studio/issues
The workaround solution here is launch Appium server by yourself and use Remote execution in Katalon Studio. Here is a guideline to setup Appium server and connect to Katalon: How to configurate Desired Capabilities of Remote execution for Mobile test