Advanced Request Delayer od SexyWerewolf

"Request Delayer" allows you to add customizable, random delays to web requests based on specific domains or URLs. You have complete control over which requests are delayed, with the ability to specify domains and use RegExp patterns for advanced URL matching. Whether you're testing, debugging, or managing traffic, this add-on gives you the flexibility to fine-tune your browsing experience.

This is a fork from https://github.com/anasdox/request-delayer