Disable JavaScript or JQuery full screen overlap event

I'm new to here and wondering if someone could share some insight with you.

Lately I've noticed that other sites have JavaScript or Jquery events that trigger a full screen dialog. Some sites have a trigger based on time, scrolling patterns, login status, and even mouse focus on a web page.

It became a bit of a pet, which got me interrupted by what I feel is popup 2.0. The only solution I know of is disabling JS in my browser, which in the modern world is what makes the website much worse. A perfect example would be marketizator.com where the mouse focus leaves the body and this will trigger a full screen overlay. Another example would be Twitter, where you visit a profile without logging in and ask for it.

I am wondering if someone can directly link me to how I can develop my own or expose an existing method to prevent websites like this from firing on my own browser. Or even someone can identify the exact focus event that is triggered.

My skill level and knowledge with JS is very low, but I am open to learning more to solve my problem.

Thanks for any help

Dave