I'm wondering if the automatic injection causing the message Duplicate agent injection detected, turning off redundant initConfig, spells overhead? Furthermore is there a way to load the JSscript in such a way that it doesn't get injected twice?
I dont think there is a lot of overhead - but - you should definiely need to look into WHY you are injecting twice. are you combining manual and automated instrumentation? Or do you have any more insights on how this could happen?
You might also want to open a support ticket so that our colleagues can have a closer look at your configuration to figure out what this happens