So, for many of these the answer is basically "I tried this hack with good results, but then my situation changed" rather than "the hack stopped working." Leechblock was effective when I was restricting my internet usage from 9 to 5, but then I reconsidered that restriction, and now I don't use Leechblock.

Each of these hacks is generally a policy shift of some sort, which may not impact the tight constraint for some activities.