https://opensolution.org/docs/?p=en-settings Please find define( 'DEVELOPER_MODE', true ); and read instruction. There you can find information for what developer mode is useful for.
Maybe this texts from instruction helps you:
1. When a final version of a website is published on a server, it's good to disable this option (by commenting the definition line). To comment a line add // characters in front of the code. So after commenting the line should look like this: //define( 'DEVELOPER_MODE', true );
2. Of course you can yourself configure the script to restrict your customer's access to whatever options you want. Look for the if( !defined( 'DEVELOPER_MODE' ) ){ code in the configuration file. Below that code you will find a list of variables responsible for disabling functions in the script when the developer mode is disabled.
