Ok so after a little digging, you can add settings to the global user JSON file. From your command pallette (cmd+shift+p) search for the settings file (see image).

 "r.rterm.option": [
        "--r-binary=your_path_to_R", // Replace with your R path 
        "--no-save", // Optional: Prevent saving workspaces
        "--no-restore", // Optional: Prevent restoring workspaces
        "r.rterm.mac": "/Your_Path",  // Replace with the Radian path from above
        "r.bracketedPaste": true  // Enables chunked code execution
        "r.alwaysUseActiveTerminal": true, // Enables cmd+enter execution
        "r.bracketedPaste": true,
        "r.sessionWatcher": true
    ]