What are the ideal scripts to be included?

Any script that is not crucial for rendering the first view or above fold contents. 3rd party scripts like tracking scripts, chat plugins, etc are ideal.

What should I put in include keywords

Any keyword inside your inline script that uniquely identifies that script. For example "fbevents.js" for Facebook Pixel, "gtag" for Google Tag Manager, "customerchat.js" for Facebook Customer Chat plugin.

How is it different from defer

defer tells the browser to download the script when found and execute it when HTML parsing is complete. When you include a script in Flying Scripts, those scripts won't be executed until there is user interaction.

What is user interaction?

Events from the user like mouse hover, scroll, keyboard input, touch in a mobile device, etc.

What is timeout?

Even if there is no user interaction, scripts will be executed after the specified timeout.