Enable/Disable Analytics in development ?  #29

I'm working on my team workflow for analytics and i'm looking for a way to Enable/Disable analytics in development environment.

//package.json
    "start": "react-scripts start",
    "start:analytics": "REACT_APP_SEGMENT="Dev key" react-scripts start",

This seems to work but i don't really understand how analytics script work behind the hood but it seems to save all analytics events done even if the script doesn't load .

Is this acceptable or could you show me how to prevent sending data in this case ?