In a similar vein, does anybody know of a browser extension that lets me throttle bandwidth for a defined list of domains? Or some piece of software I could run on a Mac that would accomplish the same thing?

For the longest time I've wanted to make Twitter load at a snail's pace. Make it so everything takes just long enough that I don't mindlessly scroll for long periods of time. In my mind, it's a nice middle ground between blocking entirely and allowing full access.

I can mimic it via "Throttling" in DevTools > Network with a custom profile (or one of the 3G profiles), but I'm looking for something that doesn't need DevTools open all the time to work.